@node Contributing @chapter Contributing This project is a cooperative effort, and we need your help to make it grow! Please get in touch with us on @email{guix-devel@@gnu.org} and @code{#guix} on the Libera Chat IRC network. We welcome ideas, bug reports, patches, and anything that may be helpful to the project. We particularly welcome help on packaging (@pxref{Packaging Guidelines}). @cindex code of conduct, of contributors @cindex contributor covenant We want to provide a warm, friendly, and harassment-free environment, so that anyone can contribute to the best of their abilities. To this end our project uses a ``Contributor Covenant'', which was adapted from @url{https://contributor-covenant.org/}. You can find a local version in the @file{CODE-OF-CONDUCT} file in the source tree. Contributors are not required to use their legal name in patches and on-line communication; they can use any name or pseudonym of their choice. @menu * Requirements:: Software needed to build and run Guix. * Building from Git:: The latest and greatest. * Running the Test Suite:: Testing Guix. * Running Guix Before It Is Installed:: Hacker tricks. * The Perfect Setup:: The right tools. * Alternative Setups:: Other possible tools that do the job. * Source Tree Structure:: Source code guided tour. * Packaging Guidelines:: Growing the distribution. * Coding Style:: Hygiene of the contributor. * Submitting Patches:: Share your work. * Tracking Bugs and Changes:: Keeping it all organized. * Commit Access:: Pushing to the official repository. * Reviewing the Work of Others:: Some guidelines for sharing reviews. * Updating the Guix Package:: Updating the Guix package definition. * Writing Documentation:: Improving documentation in GNU Guix. * Translating Guix:: Make Guix speak your native language. @end menu @node Requirements @section Requirements You can easily hack on Guix itself using Guix and Git, which we use for version control (@pxref{Building from Git}). But when packaging Guix for foreign distros or when bootstrapping on systems without Guix, and if you decide to not just trust and install our readily made binary (@pxref{Binary Installation}), you can download a release version of our reproducible source tarball and read on. This section lists requirements when building Guix from source. The build procedure for Guix is the same as for other GNU software, and is not covered here. Please see the files @file{README} and @file{INSTALL} in the Guix source tree for additional details. @cindex official website GNU Guix is available for download from its website at @url{https://www.gnu.org/software/guix/}. GNU Guix depends on the following packages: @itemize @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x, version 3.0.3 or later; @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version 0.1.0 or later; @item @uref{https://gitlab.com/gnutls/guile/, Guile-GnuTLS} (@pxref{Guile Preparations, how to install the GnuTLS bindings for Guile,, gnutls-guile, GnuTLS-Guile})@footnote{The Guile bindings to @uref{https://gnutls.org/, GnuTLS} were distributed as part of GnuTLS until version 3.7.8 included.}; @item @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0 or later; @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib}, version 0.1.0 or later; @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib}; @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi}; @item @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.5.0 or later; @item @uref{https://git-scm.com, Git} (yes, both!); @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 4.3.0 or later; @item @url{https://www.gnu.org/software/make/, GNU Make}. @end itemize The following depend2015-06-21gnu: jemalloc: Build with gcc-4.8 on i686....* gnu/packages/jemalloc.scm (jemalloc)[native-inputs]: When compiling natively on i686, add gcc-4.8. Mark H Weaver 2015-04-18gnu: Add jemalloc....* gnu/packages/jemalloc.scm: New file. * gnu-system.am (GNU_SYSTEM_MODULES): Add it. 宋文武 SQLite 3}; @item @url{https://gcc.gnu.org, GCC's g++}, with support for the C++11 standard. @end itemize @node Building from Git @section Building from Git If you want to hack Guix itself, it is recommended to use the latest version from the Git repository: @example git clone https://git.savannah.gnu.org/git/guix.git @end example @cindex authentication, of a Guix checkout How do you ensure that you obtained a genuine copy of the repository? To do that, run @command{guix git authenticate}, passing it the commit and OpenPGP fingerprint of the @dfn{channel introduction} (@pxref{Invoking guix git authenticate}): @c The commit and fingerprint below must match those of the channel @c introduction in '%default-channels'. @example git fetch origin keyring:keyring guix git authenticate 9edb3f66fd807b096b48283debdcddccfea34bad \ "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA" @end example @noindent This command completes with exit code zero on success; it prints an error message and exits with a non-zero code otherwise. As you can see, there is a chicken-and-egg problem: you first need to have Guix installed. Typically you would install Guix System (@pxref{System Installation}) or Guix on top of another distro (@pxref{Binary Installation}); in either case, you would verify the OpenPGP signature on the installation medium. This ``bootstraps'' the trust chain. The easiest way to set up a development environment for Guix is, of course, by using Guix! The following command starts a new shell where all the dependencies and appropriate environment variables are set up to hack on Guix: @example guix shell -D guix -CPW @end example or even, from within a Git worktree for Guix: @example guix shell -CPW @end example If @option{-C} (short for @option{--container}) is not supported on your system, try @command{--pure} instead of @option{-CPW}. @xref{Invoking guix shell}, for more information on that command. If you are unable to use Guix when building Guix from a checkout, the following are the required packages in addition to those mentioned in the installation instructions (@pxref{Requirements}). @itemize @item @url{https://gnu.org/software/autoconf/, GNU Autoconf}; @item @url{https://gnu.org/software/automake/, GNU Automake}; @item @url{https://gnu.org/software/gettext/, GNU Gettext}; @item @url{https://gnu.org/software/texinfo/, GNU Texinfo}; @item @url{https://www.graphviz.org/, Graphviz}; @item @url{https://www.gnu.org/software/help2man/, GNU Help2man (optional)}. @end itemize On Guix, extra dependencies can be added by instead running @command{guix shell}: @example guix shell -D guix help2man git strace --pure @end example From there you can generate the build system infrastructure using Autoconf and Automake: @example ./bootstrap @end example If you get an error like this one: @example configure.ac:46: error: possibly undefined macro: PKG_CHECK_MODULES @end example @noindent it probably means that Autoconf couldn’t find @file{pkg.m4}, which is provided by pkg-config. Make sure that @file{pkg.m4} is available. The same holds for the @file{guile.m4} set of macros provided by Guile. For instance, if you installed Automake in @file{/usr/local}, it wouldn’t look for @file{.m4} files in @file{/usr/share}. In that case, you have to invoke the following command: @example export ACLOCAL_PATH=/usr/share/aclocal @end example @xref{Macro Search Path,,, automake, The GNU Automake Manual}, for more information. @cindex state directory @cindex localstatedir @cindex system configuration directory @cindex sysconfdir Then, run: @example ./configure @end example @noindent ... where @file{/var} is the normal @code{localstatedir} value (@pxref{The Store}, for information about this) and @file{/etc} is the normal @code{sysconfdir} value. Note that you will probably not run @command{make install} at the end (you don't have to) but it's still important to pass the right @code{localstatedir} and @code{sysconfdir} values, which get recorded in the @code{(guix config)} Guile module. Finally, you can build Guix and, if you feel so inclined, run the tests (@pxref{Running the Test Suite}): @example make make check @end example @noindent If anything fails, take a look at installation instructions (@pxref{Installation}) or send a message to the @email{guix-devel@@gnu.org, mailing list}. From there on, you can authenticate all the commits included in your checkout by running: @example guix git authenticate \ 9edb3f66fd807b096b48283debdcddccfea34bad \ "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA" @end example The first run takes a couple of minutes, but subsequent runs are faster. On subsequent runs, you can run the command without any arguments since the @dfn{introduction} (the commit ID and OpenPGP fingerprints above) will have been recorded@footnote{This requires a recent version of Guix, from May 2024 or more recent.}: @example guix git authenticate @end example When your configuration for your local Git repository doesn't match the default one, you can provide the reference for the @code{keyring} branch @i{via} the @option{-k} option. The following example assumes that you have a Git remote called @samp{myremote} pointing to the official repository: @example guix git authenticate \ -k myremote/keyring \ 9edb3f66fd807b096b48283debdcddccfea34bad \ "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA" @end example @xref{Invoking guix git authenticate}, for more information on this command. @quotation Note By default, hooks are installed such that @command{guix git authenticate} is invoked anytime you run @command{git pull} or @command{git push}. @end quotation After updating the repository, @command{make} might fail with an error similar to the following example: @example error: failed to load 'gnu/packages/linux.scm': ice-9/eval.scm:293:34: In procedure abi-check: #>: record ABI mismatch; recompilation needed @end example This means that one of the record types that Guix defines (in this example, the @code{origin} record) has changed, and all of guix needs to be recompiled to take that change into account. To do so, run @command{make clean-go} followed by @command{make}. Should @command{make} fail with an Automake error message after updating, you need to repeat the steps outlined in this section, commencing with @command{./bootstrap}. @node Running the Test Suite @section Running the Test Suite @cindex test suite After a successful @command{configure} and @code{make} run, it is a good idea to run the test suite. It can help catch issues with the setup or environment, or bugs in Guix itself---and really, reporting test failures is a good way to help improve the software. To run the test suite, type: @example make check @end example Test cases can run in parallel: you can use the @code{-j} option of GNU@tie{}make to speed things up. The first run may take a few minutes on a recent machine; subsequent runs will be faster because the store that is created for test purposes will already have various things in cache. It is also possible to run a subset of the tests by defining the @code{TESTS} makefile variable as in this example: @example make check TESTS="tests/store.scm tests/cpio.scm" @end example By default, tests results are displayed at a file level. In order to see the details of every individual test cases, it is possible to define the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example: @example make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no" @end example The underlying SRFI 64 custom Automake test driver used for the 'check' test suite (located at @file{build-aux/test-driver.scm}) also allows selecting which test cases to run at a finer level, via its @option{--select} and @option{--exclude} options. Here's an example, to run all the test cases from the @file{tests/packages.scm} test file whose names start with ``transaction-upgrade-entry'': @example export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry" make check TESTS="tests/packages.scm" @end example Those wishing to inspect the results of failed tests directly from the command line can add the @option{--errors-only=yes} option to the @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE} Automake makefile variable, as in: @example make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1 @end example The @option{--show-duration=yes} option can be used to print the duration of the individual test cases, when used in combination with @option{--brief=no}: @example make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes" @end example @xref{Parallel Test Harness,,,automake,GNU Automake} for more information about the Automake Parallel Test Harness. Upon failure, please email @email{bug-guix@@gnu.org} and attach the @file{test-suite.log} file. Please specify the Guix version being used as well as version numbers of the dependencies (@pxref{Requirements}) in your message. Guix also comes with a whole-system test suite that tests complete Guix System instances. It can only run on systems where Guix is already installed, using: @example make check-system @end example @noindent or, again, by defining @code{TESTS} to select a subset of tests to run: @example make check-system TESTS="basic mcron" @end example These system tests are defined in the @code{(gnu tests @dots{})} modules. They work by running the operating systems under test with lightweight instrumentation in a virtual machine (VM). They can be computationally intensive or rather cheap, depending on whether substitutes are available for their dependencies (@pxref{Substitutes}). Some of them require a lot of storage space to hold VM images. If you encounter an error like: @example Compiling Scheme modules... ice-9/eval.scm:142:16: In procedure compile-top-call: error: all-system-tests: unbound variable hint: Did you forget `(use-modules (gnu tests))'? @end example @noindent there may be inconsistencies in the work tree from previous builds. To resolve this, try running @command{make clean-go} followed by @command{make}. Again in case of test failures, please send @email{bug-guix@@gnu.org} all the details. @node Running Guix Before It Is Installed @section Running Guix Before It Is Installed In order to keep a sane working environment, you will find it useful to test the changes made in your local source tree checkout without actually installing them. So that you can distinguish between your ``end-user'' hat and your ``motley'' costume. To that end, all the command-line tools can be used even if you have not run @code{make install}. To do that, you first need to have an environment with all the dependencies available (@pxref{Building from Git}), and then simply prefix each command with @command{./pre-inst-env} (the @file{pre-inst-env} script lives in the top build tree of Guix; @pxref{Building from Git} to generate it). As an example, here is how you would build the @code{hello} package as defined in your working tree (this assumes @command{guix-daemon} is already running on your system; it's OK if it's a different version): @example $ ./pre-inst-env guix build hello @end example @noindent Similarly, an example for a Guile session using the Guix modules: @example $ ./pre-inst-env guile -c '(use-modules (guix utils)) (pk (%current-system))' ;;; ("x86_64-linux") @end example @noindent @cindex REPL @cindex read-eval-print loop @dots{} and for a REPL (@pxref{Using Guix Interactively}): @example $ ./pre-inst-env guile scheme@@(guile-user)> ,use(guix) scheme@@(guile-user)> ,use(gnu) scheme@@(guile-user)> (define snakes (fold-packages (lambda (package lst) (if (string-prefix? "python" (package-name package)) (cons package lst) lst)) '())) scheme@@(guile-user)> (length snakes) $1 = 361 @end example If you are hacking on the daemon and its supporting code or if @command{guix-daemon} is not already running on your system, you can launch it straight from the build tree@footnote{The @option{-E} flag to @command{sudo} guarantees that @code{GUILE_LOAD_PATH} is correctly set such that @command{guix-daemon} and the tools it uses can find the Guile modules they need.}: @example $ sudo -E ./pre-inst-env guix-daemon --build-users-group=guixbuild @end example The @command{pre-inst-env} script sets up all the environment variables necessary to support this, including @env{PATH} and @env{GUILE_LOAD_PATH}. Note that @command{./pre-inst-env guix pull} does @emph{not} upgrade the local source tree; it simply updates the @file{~/.config/guix/current} symlink (@pxref{Invoking guix pull}). Run @command{git pull} instead if you want to upgrade your local source tree. Sometimes, especially if you have recently updated your repository, running @command{./pre-inst-env} will print a message similar to the following example: @example ;;; note: source file /home/user/projects/guix/guix/progress.scm ;;; newer than compiled /home/user/projects/guix/guix/progress.go @end example This is only a note and you can safely ignore it. You can get rid of the message by running @command{make -j4}. Until you do, Guile will run slightly slower because it will interpret the code instead of using prepared Guile object (@file{.go}) files. You can run @command{make} automatically as you work using @command{watchexec} from the @code{watchexec} package. For example, to build again each time you update a package file, run @samp{watchexec -w gnu/packages -- make -j4}. @node The Perfect Setup @section The Perfect Setup The Perfect Setup to hack on Guix is basically the perfect setup used for Guile hacking (@pxref{Using Guile in Emacs,,, guile, Guile Reference Manual}). First, you need more than an editor, you need @url{https://www.gnu.org/software/emacs, Emacs}, empowered by the wonderful @url{https://nongnu.org/geiser/, Geiser}. To set that up, run: @example guix install emacs guile emacs-geiser emacs-geiser-guile @end example Geiser allows for interactive and incremental development from within Emacs: code compilation and evaluation from within buffers, access to on-line documentation (docstrings), context-sensitive completion, @kbd{M-.} to jump to an object definition, a REPL to try out your code, and more (@pxref{Introduction,,, geiser, Geiser User Manual}). If you allow Emacs to load the @file{.dir-locals.el} file at the root of the project checkout, it will cause Geiser to automatically add the local Guix sources to the Guile load path. To actually edit the code, Emacs already has a neat Scheme mode. But in addition to that, you must not miss @url{https://www.emacswiki.org/emacs/ParEdit, Paredit}. It provides facilities to directly operate on the syntax tree, such as raising an s-expression or wrapping it, swallowing or rejecting the following s-expression, etc. @cindex code snippets @cindex templates @cindex reducing boilerplate We also provide templates for common git commit messages and package definitions in the @file{etc/snippets} directory. These templates can be used to expand short trigger strings to interactive text snippets. If you use @url{https://joaotavora.github.io/yasnippet/, YASnippet}, you may want to add the @file{etc/snippets/yas} snippets directory to the @var{yas-snippet-dirs} variable. If you use @url{https://github.com/minad/tempel/, Tempel}, you may want to add the @file{etc/snippets/tempel/*} path to the @var{tempel-path} variable in Emacs. @lisp ;; @r{Assuming the Guix checkout is in ~/src/guix.} ;; @r{Yasnippet configuration} (with-eval-after-load 'yasnippet (add-to-list 'yas-snippet-dirs "~/src/guix/etc/snippets/yas")) ;; @r{Tempel configuration} (with-eval-after-load 'tempel ;; Ensure tempel-path is a list -- it may also be a string. (unless (listp 'tempel-path) (setq tempel-path (list tempel-path))) (add-to-list 'tempel-path "~/src/guix/etc/snippets/tempel/*")) @end lisp The commit message snippets depend on @url{https://magit.vc/, Magit} to display staged files. When editing a commit message type @code{add} followed by @kbd{TAB} to insert a commit message template for adding a package; type @code{update} followed by @kbd{TAB} to insert a template for updating a package; type @code{https} followed by @kbd{TAB} to insert a template for changing the home page URI of a package to HTTPS. The main snippet for @code{scheme-mode} is triggered by typing @code{package...} followed by @kbd{TAB}. This snippet also inserts the trigger string @code{origin...}, which can be expanded further. The @code{origin} snippet in turn may insert other trigger strings ending on @code{...}, which also can be expanded further. @cindex insert or update copyright @cindex @code{M-x guix-copyright} @cindex @code{M-x copyright-update} We additionally provide insertion and automatic update of a copyright in @file{etc/copyright.el}. You may want to set your full name, mail, and load a file. @lisp (setq user-full-name "Alice Doe") (setq user-mail-address "alice@@mail.org") ;; @r{Assuming the Guix checkout is in ~/src/guix.} (load-file "~/src/guix/etc/copyright.el") @end lisp To insert a copyright at the current line invoke @code{M-x guix-copyright}. To update a copyright you need to specify a @code{copyright-names-regexp}. @lisp (setq copyright-names-regexp (format "%s <%s>" user-full-name user-mail-address)) @end lisp You can check if your copyright is up to date by evaluating @code{M-x copyright-update}. If you want to do it automatically after each buffer save then add @code{(add-hook 'after-save-hook 'copyright-update)} in Emacs. @node Viewing Bugs within Emacs @subsection Viewing Bugs within Emacs Emacs has a nice minor mode called @code{bug-reference}, which, when combined with @samp{emacs-debbugs} (the Emacs package), can be used to open links such as @samp{} or @samp{} as bug report buffers. From there you can easily consult the email thread via the Gnus interface, reply or modify the bug status, all without leaving the comfort of Emacs! Below is a sample configuration to add to your @file{~/.emacs} configuration file: @lisp ;;; Bug references. (require 'bug-reference) (add-hook 'prog-mode-hook #'bug-reference-prog-mode) (add-hook 'gnus-mode-hook #'bug-reference-mode) (add-hook 'erc-mode-hook #'bug-reference-mode) (add-hook 'gnus-summary-mode-hook #'bug-reference-mode) (add-hook 'gnus-article-mode-hook #'bug-reference-mode) ;;; This extends the default expression (the top-most, first expression ;;; provided to 'or') to also match URLs such as ;;; or . ;;; It is also extended to detect "Fixes: #NNNNN" git trailers. (setq bug-reference-bug-regexp (rx (group (or (seq word-boundary (or (seq (char "Bb") "ug" (zero-or-one " ") (zero-or-one "#")) (seq (char "Pp") "atch" (zero-or-one " ") "#") (seq (char "Ff") "ixes" (zero-or-one ":") (zero-or-one " ") "#") (seq "RFE" (zero-or-one " ") "#") (seq "PR " (one-or-more (char "a-z+-")) "/")) (group (one-or-more (char "0-9")) (zero-or-one (seq "#" (one-or-more (char "0-9")))))) (seq (? "<") "https://bugs.gnu.org/" (group-n 2 (one-or-more (char "0-9"))) (? ">")) (seq (? "<") "https://issues.guix.gnu.org/" (? "issue/") (group-n 2 (one-or-more (char "0-9"))) (? ">")))))) (setq bug-reference-url-format "https://issues.guix.gnu.org/%s") (require 'debbugs) (require 'debbugs-browse) (add-hook 'bug-reference-mode-hook #'debbugs-browse-mode) (add-hook 'bug-reference-prog-mode-hook #'debbugs-browse-mode) ;; The following allows Emacs Debbugs user to open the issue directly within ;; Emacs. (setq debbugs-browse-url-regexp (rx line-start "http" (zero-or-one "s") "://" (or "debbugs" "issues.guix" "bugs") ".gnu.org" (one-or-more "/") (group (zero-or-one "cgi/bugreport.cgi?bug=")) (group-n 3 (one-or-more digit)) line-end)) ;; Change the default when run as 'M-x debbugs-gnu'. (setq debbugs-gnu-default-packages '("guix" "guix-patches")) ;; Show feature requests. (setq debbugs-gnu-default-severities '("serious" "important" "normal" "minor" "wishlist")) @end lisp For more information, refer to @ref{Bug Reference,,, emacs, The GNU Emacs Manual} and @ref{Minor Mode,,, debbugs-ug, The Debbugs User Guide}. @node Alternative Setups @section Alternative Setups Alternative setups than Emacs may let you work on Guix with a similar development experience and they might work better with the tools you currently use or help you make the transition to Emacs. The options listed below only provide the alternatives to the Emacs based setup, which is the most widely used in the Guix community. If you want to really understand how is the perfect setup for Guix development supposed to work, we encourage you to read the section before this regardless the editor you choose to use. @menu * Guile Studio:: First step in your transition to Emacs. * Vim and NeoVim:: When you are evil to the root. @end menu @node Guile Studio @subsection Guile Studio Guile Studio is a pre-configured Emacs with mostly everything you need to start hacking in Guile. If you are not familiar with Emacs it makes the transition easier for you. @example guix install guile-studio @end example Guile Studio comes with Geiser preinstalled and prepared for action. @node Vim and NeoVim @subsection Vim and NeoVim Vim (and NeoVim) are also packaged in Guix, just in case you decided to go for the evil path. @example guix install vim @end example If you want to enjoy a similar development experience to that in the perfect setup, you should install several plugins to configure the editor. Vim (and NeoVim) have the equivalent to Paredit, @uref{https://www.vim.org/scripts/script.php?script_id=3998, @code{paredit.vim}}, that will help you with the structural editing of Scheme files (the support for very large files is not great, though). @example guix install vim-paredit @end example We also recommend that you run @code{:set autoindent} so that your code is automatically indented as you type. For the interaction with Git, @uref{https://www.vim.org/scripts/script.php?script_id=2975, @code{fugitive.vim}} is the most commonly used plugin: @example guix install vim-fugitive @end example And of course if you want to interact with Guix directly from inside of vim, using the built-in terminal emulator, we have our very own @code{guix.vim} package! @example guix install vim-guix-vim @end example In NeoVim you can even make a similar setup to Geiser using @url{https://conjure.fun/, Conjure} that lets you connect to a running Guile process and inject your code there live (sadly it's not packaged in Guix yet). @node Source Tree Structure @section Source Tree Structure @cindex structure, of the source tree If you're willing to contribute to Guix beyond packages, or if you'd like to learn how it all fits together, this section provides a guided tour in the code base that you may find useful. Overall, the Guix source tree contains almost exclusively Guile @dfn{modules}, each of which can be seen as an independent library (@pxref{Modules,,, guile, GNU Guile Reference Manual}). The following table gives an overview of the main directories and what they contain. Remember that in Guile, each module name is derived from its file name---e.g., the module in file @file{guix/packages.scm} is called @code{(guix packages)}. @table @file @item guix This is the location of core Guix mechanisms. To illustrate what is meant by ``core'', here are a few examples, starting from low-level tools and going towards higher-level tools: @table @code @item (guix store) Connecting to and interacting with the build daemon (@pxref{The Store}). @item (guix derivations) Creating derivations (@pxref{Derivations}). @item (guix gexps) Writing G-expressions (@pxref{G-Expressions}). @item (guix packages) Defining packages and origins (@pxref{package Reference}). @item (guix download) @itemx (guix git-download) The @code{url-fetch} and @code{git-fetch} origin download methods (@pxref{origin Reference}). @item (guix swh) Fetching source code from the @uref{https://archive.softwareheritage.org,Software Heritage archive}. @item (guix search-paths) Implementing search paths (@pxref{Search Paths}). @item (guix build-system) The build system interface (@pxref{Build Systems}). @item (guix profiles) Implementing profiles. @end table @cindex build system, directory structure @item guix/build-system This directory contains specific build system implementations (@pxref{Build Systems}), such as: @table @code @item (guix build-system gnu) the GNU build system; @item (guix build-system cmake) the CMake build system; @item (guix build-system pyproject) The Python ``pyproject'' build system. @end table @item guix/build This contains code generally used on the ``build side'' (@pxref{G-Expressions, strata of code}). This includes code used to build packages or other operating system components, as well as utilities: @table @code @item (guix build utils) Utilities for package definitions and more (@pxref{Build Utilities}). @item (guix build gnu-build-system) @itemx (guix build cmake-build-system) @itemx (guix build pyproject-build-system) Implementation of build systems, and in particular definition of their build phases (@pxref{Build Phases}). @item (guix build syscalls) Interface to the C library and to Linux system calls. @end table @cindex command-line tools, as Guile modules @cindex command modules @item guix/scripts This contains modules corresponding to @command{guix} sub-commands. For example, the @code{(guix scripts shell)} module exports the @code{guix-shell} procedure, which directly corresponds to the @command{guix shell} command (@pxref{Invoking guix shell}). @cindex importer modules @item guix/import This contains supporting code for the importers and updaters (@pxref{Invoking guix import}, and @pxref{Invoking guix refresh}). For example, @code{(guix import pypi)} defines the interface to PyPI, which is used by the @code{guix import pypi} command. @end table The directories we have seen so far all live under @file{guix/}. The other important place is the @file{gnu/} directory, which contains primarily package definitions as well as libraries and tools for Guix System (@pxref{System Configuration}) and Guix Home (@pxref{Home Configuration}), all of which build upon functionality provided by @code{(guix @dots{})} modules@footnote{For this reason, @code{(guix @dots{})} modules must generally not depend on @code{(gnu @dots{})} modules, with notable exceptions: @code{(guix build-system @dots{})} modules may look up packages at run time---e.g., @code{(guix build-system cmake)} needs to access the @code{cmake} variable at run time---, @code{(guix scripts @dots{})} often rely on @code{(gnu @dots{})} modules, and the same goes for some of the @code{(guix import @dots{})} modules.}. @table @file @cindex package modules @item gnu/packages This is by far the most crowded directory of the source tree: it contains @dfn{package modules} that export package definitions (@pxref{Package Modules}). A few examples: @table @code @item (gnu packages base) Module providing ``base'' packages: @code{glibc}, @code{coreutils}, @code{grep}, etc. @item (gnu packages guile) Guile and core Guile packages. @item (gnu packages linux) The Linux-libre kernel and related packages. @item (gnu packages python) Python and core Python packages. @item (gnu packages python-xyz) Miscellaneous Python packages (we were not very creative). @end table In any case, you can jump to a package definition using @command{guix edit} (@pxref{Invoking guix edit}) and view its location with @command{guix show} (@pxref{Invoking guix package}). @findex search-patches @item gnu/packages/patches This directory contains patches applied against packages and obtained using the @code{search-patches} procedure. @item gnu/services This contains service definitions, primarily for Guix System (@pxref{Services}) but some of them are adapted and reused for Guix Home as we will see below. Examples: @table @code @item (gnu services) The service framework itself, which defines the service and service type data types (@pxref{Service Composition}). @item (gnu services base) ``Base'' services (@pxref{Base Services}). @item (gnu services desktop) ``Desktop'' services (@pxref{Desktop Services}). @item (gnu services shepherd) Support for Shepherd services (@pxref{Shepherd Services}). @end table You can jump to a service definition using @command{guix system edit} and view its location with @command{guix system search} (@pxref{Invoking guix system}). @item gnu/system These are core Guix System modules, such as: @table @code @item (gnu system) Defines @code{operating-system} (@pxref{operating-system Reference}). @item (gnu system file-systems) Defines @code{file-system} (@pxref{File Systems}). @item (gnu system mapped-devices) Defines @code{mapped-device} (@pxref{Mapped Devices}). @end table @item gnu/build These are modules that are either used on the ``build side'' when building operating systems or packages, or at run time by operating systems. @table @code @item (gnu build accounts) Creating @file{/etc/passwd}, @file{/etc/shadow}, etc. (@pxref{User Accounts}). @item (gnu build activation) Activating an operating system at boot time or reconfiguration time. @item (gnu build file-systems) Searching, checking, and mounting file systems. @item (gnu build linux-boot) @itemx (gnu build hurd-boot) Booting GNU/Linux and GNU/Hurd operating systems. @item (gnu build linux-initrd) Creating a Linux initial RAM disk (@pxref{Initial RAM Disk}). @end table @item gnu/home This contains all things Guix Home (@pxref{Home Configuration}); examples: @table @code @item (gnu home services) Core services such as @code{home-files-service-type}. @item (gnu home services ssh) SSH-related services (@pxref{Secure Shell}). @end table @item gnu/installer This contains the text-mode graphical system installer (@pxref{Guided Graphical Installation}). @item gnu/machine These are the @dfn{machine abstractions} used by @command{guix deploy} (@pxref{Invoking guix deploy}). @item gnu/tests This contains system tests---tests that spawn virtual machines to check that system services work as expected (@pxref{Running the Test Suite}). @end table Last, there's also a few directories that contain files that are @emph{not} Guile modules: @table @file @item nix This is the C++ implementation of @command{guix-daemon}, inherited from Nix (@pxref{Invoking guix-daemon}). @item tests These are unit tests, each file corresponding more or less to one module, in particular @code{(guix @dots{})} modules (@pxref{Running the Test Suite}). @item doc This is the documentation in the form of Texinfo files: this manual and the Cookbook. @xref{Writing a Texinfo File,,, texinfo, GNU Texinfo}, for information on Texinfo markup language. @item po This is the location of translations of Guix itself, of package synopses and descriptions, of the manual, and of the cookbook. Note that @file{.po} files that live here are pulled directly from Weblate (@pxref{Translating Guix}). @item etc Miscellaneous files: shell completions, support for systemd and other init systems, Git hooks, etc. @end table With all this, a fair chunk of your operating system is at your fingertips! Beyond @command{grep} and @command{git grep}, @pxref{The Perfect Setup} on how to navigate code from your editor, and @pxref{Using Guix Interactively} for information on how to use Scheme modules interactively. Enjoy! @node Packaging Guidelines @section Packaging Guidelines @cindex packages, creating The GNU distribution is nascent and may well lack some of your favorite packages. This section describes how you can help make the distribution grow. Free software packages are usually distributed in the form of @dfn{source code tarballs}---typically @file{tar.gz} files that contain all the source files. Adding a package to the distribution means essentially two things: adding a @dfn{recipe} that describes how to build the package, including a list of other packages required to build it, and adding @dfn{package metadata} along with that recipe, such as a description and licensing information. In Guix all this information is embodied in @dfn{package definitions}. Package definitions provide a high-level view of the package. They are written using the syntax of the Scheme programming language; in fact, for each package we define a variable bound to the package definition, and export that variable from a module (@pxref{Package Modules}). However, in-depth Scheme knowledge is @emph{not} a prerequisite for creating packages. For more information on package definitions, @pxref{Defining Packages}. Once a package definition is in place, stored in a file in the Guix source tree, it can be tested using the @command{guix build} command (@pxref{Invoking guix build}). For example, assuming the new package is called @code{gnew}, you may run this command from the Guix build tree (@pxref{Running Guix Before It Is Installed}): @example ./pre-inst-env guix build gnew --keep-failed @end example Using @code{--keep-failed} makes it easier to debug build failures since it provides access to the failed build tree. Another useful command-line option when debugging is @code{--log-file}, to access the build log. If the package is unknown to the @command{guix} command, it may be that the source file contains a syntax error, or lacks a @code{define-public} clause to export the package variable. To figure it out, you may load the module from Guile to get more information about the actual error: @example ./pre-inst-env guile -c '(use-modules (gnu packages gnew))' @end example Once your package builds correctly, please send us a patch (@pxref{Submitting Patches}). Well, if you need help, we will be happy to help you too. Once the patch is committed in the Guix repository, the new package automatically gets built on the supported platforms by @url{https://@value{SUBSTITUTE-SERVER-1}, our continuous integration system}. @cindex substituter Users can obtain the new package definition simply by running @command{guix pull} (@pxref{Invoking guix pull}). When @code{@value{SUBSTITUTE-SERVER-1}} is done building the package, installing the package automatically downloads binaries from there (@pxref{Substitutes}). The only place where human intervention is needed is to review and apply the patch. @menu * Software Freedom:: What may go into the distribution. * Package Naming:: What's in a name? * Version Numbers:: When the name is not enough. * Synopses and Descriptions:: Helping users find the right package. * Snippets versus Phases:: Whether to use a snippet, or a build phase. * Cyclic Module Dependencies:: Going full circle. * Emacs Packages:: Your Elisp fix. * Python Modules:: A touch of British comedy. * Perl Modules:: Little pearls. * Java Packages:: Coffee break. * Rust Crates:: Beware of oxidation. * Elm Packages:: Trees of browser code * Fonts:: Fond of fonts. @end menu @node Software Freedom @subsection Software Freedom @c Adapted from http://www.gnu.org/philosophy/philosophy.html. @cindex free software The GNU operating system has been developed so that users can have freedom in their computing. GNU is @dfn{free software}, meaning that users have the @url{https://www.gnu.org/philosophy/free-sw.html,four essential freedoms}: to run the program, to study and change the program in source code form, to redistribute exact copies, and to distribute modified versions. Packages found in the GNU distribution provide only software that conveys these four freedoms. In addition, the GNU distribution follow the @url{https://www.gnu.org/distros/free-system-distribution-guidelines.html,free software distribution guidelines}. Among other things, these guidelines reject non-free firmware, recommendations of non-free software, and discuss ways to deal with trademarks and patents. Some otherwise free upstream package sources contain a small and optional subset that violates the above guidelines, for instance because this subset is itself non-free code. When that happens, the offending items are removed with appropriate patches or code snippets in the @code{origin} form of the package (@pxref{Defining Packages}). This way, @code{guix build --source} returns the ``freed'' source rather than the unmodified upstream source. @node Package Naming @subsection Package Naming @cindex package name A package actually has two names associated with it. First, there is the name of the @emph{Scheme variable}, the one following @code{define-public}. By this name, the package can be made known in the Scheme code, for instance as input to another package. Second, there is the string in the @code{name} field of a package definition. This name is used by package management commands such as @command{guix package} and @command{guix build}. Both are usually the same and correspond to the lowercase conversion of the project name chosen upstream, with underscores replaced with hyphens. For instance, GNUnet is available as @code{gnunet}, and SDL_net as @code{sdl-net}. A noteworthy exception to this rule is when the project name is only a single character, or if an older maintained project with the same name already exists---regardless of whether it has already been packaged for Guix. Use common sense to make such names unambiguous and meaningful. For example, Guix's package for the shell called ``s'' upstream is @code{s-shell} and @emph{not} @code{s}. Feel free to ask your fellow hackers for inspiration. We do not add @code{lib} prefixes for library packages, unless these are already part of the official project name. But @pxref{Python Modules} and @ref{Perl Modules} for special rules concerning modules for the Python and Perl languages. Font package names are handled differently, @pxref{Fonts}. @node Version Numbers @subsection Version Numbers @cindex package version We usually package only the latest version of a given free software project. But sometimes, for instance for incompatible library versions, two (or more) versions of the same package are needed. These require different Scheme variable names. We use the name as defined in @ref{Package Naming} for the most recent version; previous versions use the same name, suffixed by @code{-} and the smallest prefix of the version number that may distinguish the two versions. The name inside the package definition is the same for all versions of a package and does not contain any version number. For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows: @lisp (define-public gtk+ (package (name "gtk+") (version "3.9.12") ...)) (define-public gtk+-2 (package (name "gtk+") (version "2.24.20") ...)) @end lisp If we also wanted GTK+ 3.8.2, this would be packaged as @lisp (define-public gtk+-3.8 (package (name "gtk+") (version "3.8.2") ...)) @end lisp @c See , @c for a discussion of what follows. @cindex version number, for VCS snapshots Occasionally, we package snapshots of upstream's version control system (VCS) instead of formal releases. This should remain exceptional, because it is up to upstream developers to clarify what the stable release is. Yet, it is sometimes necessary. So, what should we put in the @code{version} field? Clearly, we need to make the commit identifier of the VCS snapshot visible in the version string, but we also need to make sure that the version string is monotonically increasing so that @command{guix package --upgrade} can determine which version is newer. Since commit identifiers, notably with Git, are not monotonically increasing, we add a revision number that we increase each time we upgrade to a newer snapshot. The resulting version string looks like this: @example 2.0.11-3.cabba9e ^ ^ ^ | | `-- upstream commit ID | | | `--- Guix package revision | latest upstream version @end example It is a good idea to strip commit identifiers in the @code{version} field to, say, 7 digits. It avoids an aesthetic annoyance (assuming aesthetics have a role to play here) as well as problems related to OS limits such as the maximum shebang length (127 bytes for the Linux kernel). There are helper functions for doing this for packages using @code{git-fetch} or @code{hg-fetch} (see below). It is best to use the full commit identifiers in @code{origin}s, though, to avoid ambiguities. A typical package definition may look like this: @lisp (define my-package (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7") (revision "1")) ;Guix package revision (package (version (git-version "0.9" revision commit)) (source (origin (method git-fetch) (uri (git-reference (url "git://example.org/my-package.git") (commit commit))) (sha256 (base32 "1mbikn@dots{}")) (file-name (git-file-name name version)))) ;; @dots{} ))) @end lisp @deffn {Procedure} git-version @var{VERSION} @var{REVISION} @var{COMMIT} Return the version string for packages using @code{git-fetch}. @lisp (git-version "0.2.3" "0" "93818c936ee7e2f1ba1b315578bde363a7d43d05") @result{} "0.2.3-0.93818c9" @end lisp @end deffn @deffn {Procedure} hg-version @var{VERSION} @var{REVISION} @var{CHANGESET} Return the version string for packages using @code{hg-fetch}. It works in the same way as @code{git-version}. @end deffn @node Synopses and Descriptions @subsection Synopses and Descriptions @cindex package description @cindex package synopsis As we have seen before, each package in GNU@tie{}Guix includes a synopsis and a description (@pxref{Defining Packages}). Synopses and descriptions are important: They are what @command{guix package --search} searches, and a crucial piece of information to help users determine whether a given package suits their needs. Consequently, packagers should pay attention to what goes into them. Synopses must start with a capital letter and must not end with a period. They must not start with ``a'' or ``the'', which usually does not bring anything; for instance, prefer ``File-frobbing tool'' over ``A tool that frobs files''. The synopsis should say what the package is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines matching a pattern''. Keep in mind that the synopsis must be meaningful for a very wide audience. For example, ``Manipulate alignments in the SAM format'' might make sense for a seasoned bioinformatics researcher, but might be fairly unhelpful or even misleading to a non-specialized audience. It is a good idea to come up with a synopsis that gives an idea of the application domain of the package. In this example, this might give something like ``Manipulate nucleotide sequence alignments'', which hopefully gives the user a better idea of whether this is what they are looking for. Descriptions should take between five and ten lines. Use full sentences, and avoid using acronyms without first introducing them. Please avoid marketing phrases such as ``world-leading'', ``industrial-strength'', and ``next-generation'', and avoid superlatives like ``the most advanced''---they are not helpful to users looking for a package and may even sound suspicious. Instead, try to be factual, mentioning use cases and features. @cindex Texinfo markup, in package descriptions Descriptions can include Texinfo markup, which is useful to introduce ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you should be careful when using some characters for example @samp{@@} and curly braces which are the basic special characters in Texinfo (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces such as @command{guix show} take care of rendering it appropriately. Synopses and descriptions are translated by volunteers @uref{https://translate.fedoraproject.org/projects/guix/packages, at Weblate} so that as many users as possible can read them in their native language. User interfaces search them and display them in the language specified by the current locale. To allow @command{xgettext} to extract them as translatable strings, synopses and descriptions @emph{must be literal strings}. This means that you cannot use @code{string-append} or @code{format} to construct these strings: @lisp (package ;; @dots{} (synopsis "This is translatable") (description (string-append "This is " "*not*" " translatable."))) @end lisp Translation is a lot of work so, as a packager, please pay even more attention to your synopses and descriptions as every change may entail additional work for translators. In order to help them, it is possible to make recommendations or instructions visible to them by inserting special comments like this (@pxref{xgettext Invocation,,, gettext, GNU Gettext}): @lisp ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated. (description "ARandR is designed to provide a simple visual front end for the X11 resize-and-rotate (RandR) extension. @dots{}") @end lisp @node Snippets versus Phases @subsection Snippets versus Phases @cindex snippets, when to use The boundary between using an origin snippet versus a build phase to modify the sources of a package can be elusive. Origin snippets are typically used to remove unwanted files such as bundled libraries, nonfree sources, or to apply simple substitutions. The source derived from an origin should produce a source that can be used to build the package on any system that the upstream package supports (i.e., act as the corresponding source). In particular, origin snippets must not embed store items in the sources; such patching should rather be done using build phases. Refer to the @code{origin} record documentation for more information (@pxref{origin Reference}). @node Cyclic Module Dependencies @subsection Cyclic Module Dependencies While there cannot be circular dependencies between packages, Guile's lax module loading mechanism allows circular dependencies between Guile modules, which doesn't cause problems as long as the following conditions are followed for two modules part of a dependency cycle: @cindex rules to cope with circular module dependencies @enumerate @item Macros are not shared between the co-dependent modules @item Top-level variables are only referenced in delayed (@i{thunked}) package fields: @code{arguments}, @code{native-inputs}, @code{inputs}, @code{propagated-inputs} or @code{replacement} @item Procedures referencing top-level variables from another module are not called at the top level of a module themselves. @end enumerate Straying away from the above rules may work while there are no dependency cycles between modules, but given such cycles are confusing and difficult to troubleshoot, it is best to follow the rules to avoid introducing problems down the line. @noindent Here is a common trap to avoid: @lisp (define-public avr-binutils (package (inherit (cross-binutils "avr")) (name "avr-binutils"))) @end lisp In the above example, the @code{avr-binutils} package was defined in the module @code{(gnu packages avr)}, and the @code{cross-binutils} procedure in @code{(gnu packages cross-base)}. Because the @code{inherit} field is not delayed (thunked), it is evaluated at the top level at load time, which is problematic in the presence of module dependency cycles. This could be resolved by turning the package into a procedure instead, like: @lisp (define (make-avr-binutils) (package (inherit (cross-binutils "avr")) (name "avr-binutils"))) @end lisp Care would need to be taken to ensure the above procedure is only ever used in a package delayed fields or within another procedure also not called at the top level. @node Emacs Packages @subsection Emacs Packages @cindex emacs, packaging @cindex elisp, packaging Emacs packages should preferably use the Emacs build system (@pxref{emacs-build-system}), for uniformity and the benefits provided by its build phases, such as the auto-generation of the autoloads file and the byte compilation of the sources. Because there is no standardized way to run a test suite for Emacs packages, tests are disabled by default. When a test suite is available, it should be enabled by setting the @code{#:tests?} argument to @code{#true}. By default, the command to run the test is @command{make check}, but any command can be specified via the @code{#:test-command} argument. The @code{#:test-command} argument expects a list containing a command and its arguments, to be invoked during the @code{check} phase. The Elisp dependencies of Emacs packages are typically provided as @code{propagated-inputs} when required at run time. As for other packages, build or test dependencies should be specified as @code{native-inputs}. Emacs packages sometimes depend on resources directories that should be installed along the Elisp files. The @code{#:include} argument can be used for that purpose, by specifying a list of regexps to match. The best practice when using the @code{#:include} argument is to extend rather than override its default value (accessible via the @code{%default-include} variable). As an example, a yasnippet extension package typically include a @file{snippets} directory, which could be copied to the installation directory using: @lisp #:include (cons "^snippets/" %default-include) @end lisp When encountering problems, it is wise to check for the presence of the @code{Package-Requires} extension header in the package main source file, and whether any dependencies and their versions listed therein are satisfied. @node Python Modules @subsection Python Modules @cindex python We currently package Python 2 and Python 3, under the Scheme variable names @code{python-2} and @code{python} as explained in @ref{Version Numbers}. To avoid confusion and naming clashes with other programming languages, it seems desirable that the name of a package for a Python module contains the word @code{python}. Some modules are compatible with only one version of Python, others with both. If the package Foo is compiled with Python 3, we name it @code{python-foo}. If it is compiled with Python 2, we name it @code{python2-foo}. Python 2 packages are being removed from the distribution; please do no not submit any new Python 2 packages. If a project already contains the word @code{python}, we drop this; for instance, the module python-dateutil is packaged under the names @code{python-dateutil} and @code{python2-dateutil}. If the project name starts with @code{py} (e.g.@: @code{pytz}), we keep it and prefix it as described above. @quotation Note Currently there are two different build systems for Python packages in Guix: @var{python-build-system} and @var{pyproject-build-system}. For the longest time, Python packages were built from an informally specified @file{setup.py} file. That worked amazingly well, considering Python's success, but was difficult to build tooling around. As a result, a host of alternative build systems emerged and the community eventually settled on a @url{https://peps.python.org/pep-0517/, formal standard} for specifying build requirements. @var{pyproject-build-system} is Guix's implementation of this standard. It is considered ``experimental'' in that it does not yet support all the various PEP-517 @emph{build backends}, but you are encouraged to try it for new Python packages and report any problems. It will eventually be deprecated and merged into @var{python-build-system}. @end quotation @subsubsection Specifying Dependencies @cindex inputs, for Python packages Dependency information for Python packages is usually available in the package source tree, with varying degrees of accuracy: in the @file{pyproject.toml} file, the @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini} (the latter mostly for test dependencies). Your mission, when writing a recipe for a Python package, is to map these dependencies to the appropriate type of ``input'' (@pxref{package Reference, inputs}). Although the @code{pypi} importer normally does a good job (@pxref{Invoking guix import}), you may want to check the following check list to determine which dependency goes where. @itemize @item We currently package Python with @code{setuptools} and @code{pip} installed per default. This is about to change, and users are encouraged to use @code{python-toolchain} if they want a build environment for Python. @command{guix lint} will warn if @code{setuptools} or @code{pip} are added as native-inputs because they are generally not necessary. @item Python dependencies required at run time go into @code{propagated-inputs}. They are typically defined with the @code{install_requires} keyword in @file{setup.py}, or in the @file{requirements.txt} file. @item Python packages required only at build time---e.g., those listed under @code{build-system.requires} in @file{pyproject.toml} or with the @code{setup_requires} keyword in @file{setup.py}---or dependencies only for testing---e.g., those in @code{tests_require} or @file{tox.ini}---go into @code{native-inputs}. The rationale is that (1) they do not need to be propagated because they are not needed at run time, and (2) in a cross-compilation context, it's the ``native'' input that we'd want. Examples are the @code{pytest}, @code{mock}, and @code{nose} test frameworks. Of course if any of these packages is also required at run-time, it needs to go to @code{propagated-inputs}. @item Anything that does not fall in the previous categories goes to @code{inputs}, for example programs or C libraries required for building Python packages containing C extensions. @item If a Python package has optional dependencies (@code{extras_require}), it is up to you to decide whether to add them or not, based on their usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix size}}). @end itemize @node Perl Modules @subsection Perl Modules @cindex perl Perl programs standing for themselves are named as any other package, using the lowercase upstream name. For Perl packages containing a single class, we use the lowercase class name, replace all occurrences of @code{::} by dashes and prepend the prefix @code{perl-}. So the class @code{XML::Parser} becomes @code{perl-xml-parser}. Modules containing several classes keep their lowercase upstream name and are also prepended by @code{perl-}. Such modules tend to have the word @code{perl} somewhere in their name, which gets dropped in favor of the prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}. @node Java Packages @subsection Java Packages @cindex java Java programs standing for themselves are named as any other package, using the lowercase upstream name. To avoid confusion and naming clashes with other programming languages, it is desirable that the name of a package for a Java package is prefixed with @code{java-}. If a project already contains the word @code{java}, we drop this; for instance, the package @code{ngsjava} is packaged under the name @code{java-ngs}. For Java packages containing a single class or a small class hierarchy, we use the lowercase class name, replace all occurrences of @code{.} by dashes and prepend the prefix @code{java-}. So the class @code{apache.commons.cli} becomes package @code{java-apache-commons-cli}. @node Rust Crates @subsection Rust Crates @cindex rust Rust programs standing for themselves are named as any other package, using the lowercase upstream name. To prevent namespace collisions we prefix all other Rust packages with the @code{rust-} prefix. The name should be changed to lowercase as appropriate and dashes should remain in place. In the rust ecosystem it is common for multiple incompatible versions of a package to be used at any given time, so all package definitions should have a versioned suffix. The versioned suffix is the left-most non-zero digit (and any leading zeros, of course). This follows the ``caret'' version scheme intended by Cargo. Examples@: @code{rust-clap-2}, @code{rust-rand-0.6}. Because of the difficulty in reusing rust packages as pre-compiled inputs for other packages the Cargo build system (@pxref{Build Systems, @code{cargo-build-system}}) presents the @code{#:cargo-inputs} and @code{cargo-development-inputs} keywords as build system arguments. It would be helpful to think of these as similar to @code{propagated-inputs} and @code{native-inputs}. Rust @code{dependencies} and @code{build-dependencies} should go in @code{#:cargo-inputs}, and @code{dev-dependencies} should go in @code{#:cargo-development-inputs}. If a Rust package links to other libraries then the standard placement in @code{inputs} and the like should be used. Care should be taken to ensure the correct version of dependencies are used; to this end we try to refrain from skipping the tests or using @code{#:skip-build?} when possible. Of course this is not always possible, as the package may be developed for a different Operating System, depend on features from the Nightly Rust compiler, or the test suite may have atrophied since it was released. @node Elm Packages @subsection Elm Packages @cindex Elm Elm applications can be named like other software: their names need not mention Elm. Packages in the Elm sense (see @code{elm-build-system} under @ref{Build Systems}) are required use names of the format @var{author}@code{/}@var{project}, where both the @var{author} and the @var{project} may contain hyphens internally, and the @var{author} sometimes contains uppercase letters. To form the Guix package name from the upstream name, we follow a convention similar to Python packages (@pxref{Python Modules}), adding an @code{elm-} prefix unless the name would already begin with @code{elm-}. In many cases we can reconstruct an Elm package's upstream name heuristically, but, since conversion to a Guix-style name involves a loss of information, this is not always possible. Care should be taken to add the @code{'upstream-name} property when necessary so that @samp{guix import elm} will work correctly (@pxref{Invoking guix import}). The most notable scenarios when explicitly specifying the upstream name is necessary are: @enumerate @item When the @var{author} is @code{elm} and the @var{project} contains one or more hyphens, as with @code{elm/virtual-dom}; and @item When the @var{author} contains hyphens or uppercase letters, as with @code{Elm-Canvas/raster-shapes}---unless the @var{author} is @code{elm-explorations}, which is handled as a special case, so packages like @code{elm-explorations/markdown} do @emph{not} need to use the @code{'upstream-name} property. @end enumerate The module @code{(guix build-system elm)} provides the following utilities for working with names and related conventions: @deffn {Procedure} elm-package-origin @var{elm-name} @var{version} @ @var{hash} Returns a Git origin using the repository naming and tagging regime required for a published Elm package with the upstream name @var{elm-name} at version @var{version} with sha256 checksum @var{hash}. For example: @lisp (package (name "elm-html") (version "1.0.0") (source (elm-package-origin "elm/html" version (base32 "15k1679ja57vvlpinpv06znmrxy09lbhzfkzdc89i01qa8c4gb4a"))) ...) @end lisp @end deffn @deffn {Procedure} elm->package-name @var{elm-name} Returns the Guix-style package name for an Elm package with upstream name @var{elm-name}. Note that there is more than one possible @var{elm-name} for which @code{elm->package-name} will produce a given result. @end deffn @deffn {Procedure} guix-package->elm-name @var{package} Given an Elm @var{package}, returns the possibly-inferred upstream name, or @code{#f} the upstream name is not specified via the @code{'upstream-name} property and can not be inferred by @code{infer-elm-package-name}. @end deffn @deffn {Procedure} infer-elm-package-name @var{guix-name} Given the @var{guix-name} of an Elm package, returns the inferred upstream name, or @code{#f} if the upstream name can't be inferred. If the result is not @code{#f}, supplying it to @code{elm->package-name} would produce @var{guix-name}. @end deffn @node Fonts @subsection Fonts @cindex fonts For fonts that are in general not installed by a user for typesetting purposes, or that are distributed as part of a larger software package, we rely on the general packaging rules for software; for instance, this applies to the fonts delivered as part of the X.Org system or fonts that are part of TeX Live. To make it easier for a user to search for fonts, names for other packages containing only fonts are constructed as follows, independently of the upstream package name. The name of a package containing only one font family starts with @code{font-}; it is followed by the foundry name and a dash @code{-} if the foundry is known, and the font family name, in which spaces are replaced by dashes (and as usual, all upper case letters are transformed to lower case). For example, the Gentium font family by SIL is packaged under the name @code{font-sil-gentium}. For a package containing several font families, the name of the collection is used in the place of the font family name. For instance, the Liberation fonts consist of three families, Liberation Sans, Liberation Serif and Liberation Mono. These could be packaged separately under the names @code{font-liberation-sans} and so on; but as they are distributed together under a common name, we prefer to package them together as @code{font-liberation}. In the case where several formats of the same font family or font collection are packaged separately, a short form of the format, prepended by a dash, is added to the package name. We use @code{-ttf} for TrueType fonts, @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1 fonts. @node Coding Style @section Coding Style In general our code follows the GNU Coding Standards (@pxref{Top,,, standards, GNU Coding Standards}). However, they do not say much about Scheme, so here are some additional rules. @menu * Programming Paradigm:: How to compose your elements. * Modules:: Where to store your code? * Data Types and Pattern Matching:: Implementing data structures. * Formatting Code:: Writing conventions. @end menu @node Programming Paradigm @subsection Programming Paradigm Scheme code in Guix is written in a purely functional style. One exception is code that involves input/output, and procedures that implement low-level concepts, such as the @code{memoize} procedure. @node Modules @subsection Modules @cindex build-side modules @cindex host-side modules Guile modules that are meant to be used on the builder side must live in the @code{(guix build @dots{})} name space. They must not refer to other Guix or GNU modules. However, it is OK for a ``host-side'' module to use a build-side module. As an example, the @code{(guix search-paths)} module should not be imported and used by a package since it isn't meant to be used as a ``build-side'' module. It would also couple the module with the package's dependency graph, which is undesirable. Modules that deal with the broader GNU system should be in the @code{(gnu @dots{})} name space rather than @code{(guix @dots{})}. @node Data Types and Pattern Matching @subsection Data Types and Pattern Matching The tendency in classical Lisp is to use lists to represent everything, and then to browse them ``by hand'' using @code{car}, @code{cdr}, @code{cadr}, and co. There are several problems with that style, notably the fact that it is hard to read, error-prone, and a hindrance to proper type error reports. @findex define-record-type* @findex match-record @cindex pattern matching Guix code should define appropriate data types (for instance, using @code{define-record-type*}) rather than abuse lists. In addition, it should use pattern matching, via Guile’s @code{(ice-9 match)} module, especially when matching lists (@pxref{Pattern Matching,,, guile, GNU Guile Reference Manual}); pattern matching for records is better done using @code{match-record} from @code{(guix records)}, which, unlike @code{match}, verifies field names at macro-expansion time. When defining a new record type, keep the @dfn{record type descriptor} (RTD) private (@pxref{Records,,, guile, GNU Guile Reference Manual}, for more on records and RTDs). As an example, the @code{(guix packages)} module defines @code{} as the RTD for package records but it does not export it; instead, it exports a type predicate, a constructor, and field accessors. Exporting RTDs would make it harder to change the application binary interface (because code in other modules might be matching fields by position) and would make it trivial for users to forge records of that type, bypassing any checks we may have in the official constructor (such as ``field sanitizers''). @node Formatting Code @subsection Formatting Code @cindex formatting code @cindex coding style When writing Scheme code, we follow common wisdom among Scheme programmers. In general, we follow the @url{https://mumble.net/~campbell/scheme/style.txt, Riastradh's Lisp Style Rules}. This document happens to describe the conventions mostly used in Guile’s code too. It is very thoughtful and well written, so please do read it. Some special forms introduced in Guix, such as the @code{substitute*} macro, have special indentation rules. These are defined in the @file{.dir-locals.el} file, which Emacs automatically uses. Also note that Emacs-Guix provides @code{guix-devel-mode} mode that indents and highlights Guix code properly (@pxref{Development,,, emacs-guix, The Emacs-Guix Reference Manual}). @cindex indentation, of code @cindex formatting, of code If you do not use Emacs, please make sure to let your editor knows these rules. To automatically indent a package definition, you can also run: @example ./pre-inst-env guix style @var{package} @end example @noindent @xref{Invoking guix style}, for more information. We require all top-level procedures to carry a docstring. This requirement can be relaxed for simple private procedures in the @code{(guix build @dots{})} name space, though. Procedures should not have more than four positional parameters. Use keyword parameters for procedures that take more than four parameters. @node Submitting Patches @section Submitting Patches Development is done using the Git distributed version control system. Thus, access to the repository is not strictly necessary. We welcome contributions in the form of patches as produced by @code{git format-patch} sent to the @email{guix-patches@@gnu.org} mailing list (@pxref{Submitting patches to a project,,, git, Git User Manual}). Contributors are encouraged to take a moment to set some Git repository options (@pxref{Configuring Git}) first, which can improve the readability of patches. Seasoned Guix developers may also want to look at the section on commit access (@pxref{Commit Access}). This mailing list is backed by a Debbugs instance, which allows us to keep track of submissions (@pxref{Tracking Bugs and Changes}). Each message sent to that mailing list gets a new tracking number assigned; people can then follow up on the submission by sending email to @code{@var{ISSUE_NUMBER}@@debbugs.gnu.org}, where @var{ISSUE_NUMBER} is the tracking number (@pxref{Sending a Patch Series}). Please write commit logs in the ChangeLog format (@pxref{Change Logs,,, standards, GNU Coding Standards}); you can check the commit history for examples. You can help make the review process more efficient, and increase the chance that your patch will be reviewed quickly, by describing the context of your patch and the impact you expect it to have. For example, if your patch is fixing something that is broken, describe the problem and how your patch fixes it. Tell us how you have tested your patch. Will users of the code changed by your patch have to adjust their workflow at all? If so, tell us how. In general, try to imagine what questions a reviewer will ask, and answer those questions in advance. Before submitting a patch that adds or modifies a package definition, please run through this check list: @enumerate @item If the authors of the packaged software provide a cryptographic signature for the release tarball, make an effort to verify the authenticity of the archive. For a detached GPG signature file this would be done with the @code{gpg --verify} command. @item Take some time to provide an adequate synopsis and description for the package. @xref{Synopses and Descriptions}, for some guidelines. @item Run @code{guix lint @var{package}}, where @var{package} is the name of the new or modified package, and fix any errors it reports (@pxref{Invoking guix lint}). @item Run @code{guix style @var{package}} to format the new package definition according to the project's conventions (@pxref{Invoking guix style}). @item Make sure the package builds on your platform, using @code{guix build @var{package}}. @item We recommend you also try building the package on other supported platforms. As you may not have access to actual hardware platforms, we recommend using the @code{qemu-binfmt-service-type} to emulate them. In order to enable it, add the @code{virtualization} service module and the following service to the list of services in your @code{operating-system} configuration: @lisp (service qemu-binfmt-service-type (qemu-binfmt-configuration (platforms (lookup-qemu-platforms "arm" "aarch64")))) @end lisp Then reconfigure your system. You can then build packages for different platforms by specifying the @code{--system} option. For example, to build the "hello" package for the armhf or aarch64 architectures, you would run the following commands, respectively: @example guix build --system=armhf-linux --rounds=2 hello guix build --system=aarch64-linux --rounds=2 hello @end example @item @cindex bundling Make sure the package does not use bundled copies of software already available as separate packages. Sometimes, packages include copies of the source code of their dependencies as a convenience for users. However, as a distribution, we want to make sure that such packages end up using the copy we already have in the distribution, if there is one. This improves resource usage (the dependency is built and stored only once), and allows the distribution to make transverse changes such as applying security updates for a given software package in a single place and have them affect the whole system---something that bundled copies prevent. @item Take a look at the profile reported by @command{guix size} (@pxref{Invoking guix size}). This will allow you to notice references to other packages unwillingly retained. It may also help determine whether to split the package (@pxref{Packages with Multiple Outputs}), and which optional dependencies should be used. In particular, avoid adding @code{texlive} as a dependency: because of its extreme size, use @code{texlive-updmap.cfg} procedure instead. @item Check that dependent packages (if applicable) are not affected by the change; @code{guix refresh --list-dependent @var{package}} will help you do that (@pxref{Invoking guix refresh}). @item @cindex determinism, of build processes @cindex reproducible builds, checking Check whether the package's build process is deterministic. This typically means checking whether an independent build of the package yields the exact same result that you obtained, bit for bit. A simple way to do that is by building the same package several times in a row on your machine (@pxref{Invoking guix build}): @example guix build --rounds=2 my-package @end example This is enough to catch a class of common non-determinism issues, such as timestamps or randomly-generated output in the build result. Another option is to use @command{guix challenge} (@pxref{Invoking guix challenge}). You may run it once the package has been committed and built by @code{@value{SUBSTITUTE-SERVER-1}} to check whether it obtains the same result as you did. Better yet: Find another machine that can build it and run @command{guix publish}. Since the remote build machine is likely different from yours, this can catch non-determinism issues related to the hardware---e.g., use of different instruction set extensions---or to the operating system kernel---e.g., reliance on @code{uname} or @file{/proc} files. @item When writing documentation, please use gender-neutral wording when referring to people, such as @uref{https://en.wikipedia.org/wiki/Singular_they, singular ``they''@comma{} ``their''@comma{} ``them''}, and so forth. @item Verify that your patch contains only one set of related changes. Bundling unrelated changes together makes reviewing harder and slower. Examples of unrelated changes include the addition of several packages, or a package update along with fixes to that package. @item Please follow our code formatting rules, possibly running @command{guix style} script to do that automatically for you (@pxref{Formatting Code}). @item When possible, use mirrors in the source URL (@pxref{Invoking guix download}). Use reliable URLs, not generated ones. For instance, GitHub archives are not necessarily identical from one generation to the next, so in this case it's often better to clone the repository. Don't use the @command{name} field in the URL: it is not very useful and if the name changes, the URL will probably be wrong. @item Check if Guix builds (@pxref{Building from Git}) and address the warnings, especially those about use of undefined symbols. @item Make sure your changes do not break Guix and simulate a @code{guix pull} with: @example guix pull --url=/path/to/your/checkout --profile=/tmp/guix.master @end example @end enumerate When posting a patch to the mailing list, use @samp{[PATCH] @dots{}} as a subject, if your patch is to be applied on a branch other than @code{master}, say @code{core-updates}, specify it in the subject like @samp{[PATCH core-updates] @dots{}}. You may use your email client, the @command{git send-email} command (@pxref{Sending a Patch Series}) or the @command{mumi send-email} command (@pxref{Debbugs User Interfaces}). We prefer to get patches in plain text messages, either inline or as MIME attachments. You are advised to pay attention if your email client changes anything like line breaks or indentation which could potentially break the patches. Expect some delay when you submit your very first patch to @email{guix-patches@@gnu.org}. You have to wait until you get an acknowledgement with the assigned tracking number. Future acknowledgements should not be delayed. When a bug is resolved, please close the thread by sending an email to @email{@var{ISSUE_NUMBER}-done@@debbugs.gnu.org}. @menu * Configuring Git:: * Sending a Patch Series:: * Teams:: @end menu @node Configuring Git @subsection Configuring Git @cindex git configuration @cindex @code{git format-patch} @cindex @code{git send-email} If you have not done so already, you may wish to set a name and email that will be associated with your commits (@pxref{telling git your name, , Telling Git your name, git, Git User Manual}). If you wish to use a different name or email just for commits in this repository, you can use @command{git config --local}, or edit @file{.git/config} in the repository instead of @file{~/.gitconfig}. @cindex commit-msg hook Other important Git configuration will automatically be configured when building the project (@pxref{Building from Git}). A @file{.git/hooks/commit-msg} hook will be installed that embeds @samp{Change-Id} Git @emph{trailers} in your commit messages for traceability purposes. It is important to preserve these when editing your commit messages, particularly if a first version of your proposed changes was already submitted for review. If you have a @file{commit-msg} hook of your own you would like to use with Guix, you can place it under the @file{.git/hooks/commit-msg.d/} directory. @node Sending a Patch Series @subsection Sending a Patch Series @cindex patch series @cindex @code{git send-email} @cindex @code{git format-patch} @unnumberedsubsubsec Single Patches @anchor{Single Patches} The @command{git send-email} command is the best way to send both single patches and patch series (@pxref{Multiple Patches}) to the Guix mailing list. Sending patches as email attachments may make them difficult to review in some mail clients, and @command{git diff} does not store commit metadata. @quotation Note The @command{git send-email} command is provided by the @code{send-email} output of the @code{git} package, i.e. @code{git:send-email}. @end quotation The following command will create a patch email from the latest commit, open it in your @var{EDITOR} or @var{VISUAL} for editing, and send it to the Guix mailing list to be reviewed and merged. Assuming you have already configured Git according to @xref{Configuring Git}, you can simply use: @example $ git send-email --annotate -1 @end example @quotation Tip To add a prefix to the subject of your patch, you may use the @option{--subject-prefix} option. The Guix project uses this to specify that the patch is intended for a branch or repository other than the @code{master} branch of @url{https://git.savannah.gnu.org/cgit/guix.git}. @example git send-email --annotate --subject-prefix='PATCH core-updates' -1 @end example @end quotation The patch email contains a three-dash separator line after the commit message. You may ``annotate'' the patch with explanatory text by adding it under this line. If you do not wish to annotate the email, you may drop the @option{--annotate} option. If you need to send a revised patch, don't resend it like this or send a ``fix'' patch to be applied on top of the last one; instead, use @command{git commit --amend} or @url{https://git-rebase.io, @command{git rebase}} to modify the commit, and use the @email{@var{ISSUE_NUMBER}@@debbugs.gnu.org} address and the @option{-v} flag with @command{git send-email}. @example $ git commit --amend $ git send-email --annotate -v@var{REVISION} \ --to=@var{ISSUE_NUMBER}@@debbugs.gnu.org -1 @end example @quotation Note Due to an apparent bug in @command{git send-email}, @option{-v @var{REVISION}} (with the space) will not work; you @emph{must} use @option{-v@var{REVISION}}. @end quotation You can find out @var{ISSUE_NUMBER} either by searching on the mumi interface at @url{https://issues.guix.gnu.org} for the name of your patch or reading the acknowledgement email sent automatically by Debbugs in reply to incoming bugs and patches, which contains the bug number. @unnumberedsubsubsec Notifying Teams @anchor{Notifying Teams} @cindex teams If your git checkout has been correctly configured (@pxref{Configuring Git}), the @command{git send-email} command will automatically notify the appropriate team members, based on the scope of your changes. This relies on the @file{etc/teams.scm} script, which can also be invoked manually if you do not use the preferred @command{git send-email} command to submit patches. To list the available actions of the script, you can invoke it via the @command{etc/teams.scm help} command. For more information regarding teams, @pxref{Teams}. @quotation Note On foreign distros, you might have to use @command{./pre-inst-env git send-email} for @file{etc/teams.scm} to work. @end quotation @unnumberedsubsubsec Multiple Patches @anchor{Multiple Patches} @cindex cover letter While @command{git send-email} alone will suffice for a single patch, an unfortunate flaw in Debbugs means you need to be more careful when sending multiple patches: if you send them all to the @email{guix-patches@@gnu.org} address, a new issue will be created for each patch! When sending a series of patches, it's best to send a Git ``cover letter'' first, to give reviewers an overview of the patch series. We can create a directory called @file{outgoing} containing both our patch series and a cover letter called @file{0000-cover-letter.patch} with @command{git format-patch}. @example $ git format-patch -@var{NUMBER_COMMITS} -o outgoing \ --cover-letter --base=auto @end example We can now send @emph{just} the cover letter to the @email{guix-patches@@gnu.org} address, which will create an issue that we can send the rest of the patches to. @example $ git send-email outgoing/0000-cover-letter.patch --annotate $ rm outgoing/0000-cover-letter.patch # we don't want to resend it! @end example Ensure you edit the email to add an appropriate subject line and blurb before sending it. Note the automatically generated shortlog and diffstat below the blurb. Once the Debbugs mailer has replied to your cover letter email, you can send the actual patches to the newly-created issue address. @example $ git send-email outgoing/*.patch --to=@var{ISSUE_NUMBER}@@debbugs.gnu.org $ rm -rf outgoing # we don't need these anymore @end example Thankfully, this @command{git format-patch} dance is not necessary to send an amended patch series, since an issue already exists for the patchset. @example $ git send-email -@var{NUMBER_COMMITS} -v@var{REVISION} \ --to=@var{ISSUE_NUMBER}@@debbugs.gnu.org @end example If need be, you may use @option{--cover-letter --annotate} to send another cover letter, e.g. for explaining what's changed since the last revision, and these changes are necessary. @node Teams @subsection Teams @cindex teams There are several teams mentoring different parts of the Guix source code. To list all those teams, you can run from a Guix checkout: @example $ ./etc/teams.scm list-teams id: mentors name: Mentors description: A group of mentors who chaperone contributions by newcomers. members: + Christopher Baines + Ricardo Wurmus + Mathieu Othacehe + jgart + Ludovic Courtès @dots{} @end example You can run the following command to have the @code{Mentors} team put in CC of a patch series: @example $ git send-email --to=@var{ISSUE_NUMBER}@@debbugs.gnu.org \ --header-cmd='etc/teams.scm cc-mentors-header-cmd' *.patch @end example The appropriate team or teams can also be inferred from the modified files. For instance, if you want to send the two latest commits of the current Git repository to review, you can run: @example $ guix shell -D guix [env]$ git send-email --to=@var{ISSUE_NUMBER}@@debbugs.gnu.org -2 @end example @node Tracking Bugs and Changes @section Tracking Bugs and Changes This section describes how the Guix project tracks its bug reports, patch submissions and topic branches. @menu * The Issue Tracker:: The official bug and patch tracker. * Managing Patches and Branches:: How changes to Guix are managed. * Debbugs User Interfaces:: Ways to interact with Debbugs. * Debbugs Usertags:: Tag reports with custom labels. * Cuirass Build Notifications:: Be alerted of any breakage via RSS feeds. @end menu @node The Issue Tracker @subsection The Issue Tracker @cindex bug reports, tracking @cindex patch submissions, tracking @cindex issue tracking @cindex Debbugs, issue tracking system Bug reports and patch submissions are currently tracked using the Debbugs instance at @uref{https://bugs.gnu.org}. Bug reports are filed against the @code{guix} ``package'' (in Debbugs parlance), by sending email to @email{bug-guix@@gnu.org}, while patch submissions are filed against the @code{guix-patches} package by sending email to @email{guix-patches@@gnu.org} (@pxref{Submitting Patches}). @node Managing Patches and Branches @subsection Managing Patches and Branches @cindex branching strategy @cindex rebuild scheduling strategy Changes should be posted to @email{guix-patches@@gnu.org}. This mailing list fills the patch-tracking database (@pxref{The Issue Tracker}). It also allows patches to be picked up and tested by the quality assurance tooling; the result of that testing eventually shows up on the dashboard at @indicateurl{https://qa.guix.gnu.org/issue/@var{ISSUE_NUMBER}}, where @var{ISSUE_NUMBER} is the number assigned by the issue tracker. Leave time for a review, without committing anything. As an exception, some changes considered ``trivial'' or ``obvious'' may be pushed directly to the @code{master} branch. This includes changes to fix typos and reverting commits that caused immediate problems. This is subject to being adjusted, allowing individuals to commit directly on non-controversial changes on parts they’re familiar with. Changes which affect more than 300 dependent packages (@pxref{Invoking guix refresh}) should first be pushed to a topic branch other than @code{master}; the set of changes should be consistent---e.g., ``GNOME update'', ``NumPy update'', etc. This allows for testing: the branch will automatically show up at @indicateurl{https://qa.guix.gnu.org/branch/@var{branch}}, with an indication of its build status on various platforms. @cindex feature branches, coordination To help coordinate the merging of branches, you must create a new guix-patches issue each time you create a branch (@pxref{The Issue Tracker}). The title of the issue requesting to merge a branch should have the following format: @cindex merge requests, template @example Request for merging "@var{name}" branch @end example The @url{https://qa.guix.gnu.org/, QA infrastructure} recognizes such issues and lists the merge requests on its main page. The following points apply to managing these branches: @enumerate @item The commits on the branch should be a combination of the patches relevant to the branch. Patches not related to the topic of the branch should go elsewhere. @item Any changes that can be made on the master branch, should be made on the master branch. If a commit can be split to apply part of the changes on master, this is good to do. @item It should be possible to re-create the branch by starting from master and applying the relevant patches. @item Avoid merging master in to the branch. Prefer rebasing or re-creating the branch on top of an updated master revision. @item Minimise the changes on master that are missing on the branch prior to merging the branch in to master. This means that the state of the branch better reflects the state of master should the branch be merged. @item If you don't have commit access, create the ``Request for merging'' issue and request that someone creates the branch. Include a list of issues/patches to include on the branch. @end enumerate Normally branches will be merged in a ``first come, first merged'' manner, tracked through the guix-patches issues. If you agree on a different order with those involved, you can track this by updating which issues block@footnote{You can mark an issue as blocked by another by emailing @email{control@@debbugs.gnu.org} with the following line in the body of the email: @code{block XXXXX by YYYYY}. Where @code{XXXXX} is the number for the blocked issue, and @code{YYYYY} is the number for the issue blocking it.} which other issues. Therefore, to know which branch is at the front of the queue, look for the oldest issue, or the issue that isn't @dfn{blocked} by any other branch merges. An ordered list of branches with the open issues is available at @url{https://qa.guix.gnu.org}. Once a branch is at the front of the queue, wait until sufficient time has passed for the build farms to have processed the changes, and for the necessary testing to have happened. For example, you can check @indicateurl{https://qa.guix.gnu.org/branch/@var{branch}} to see information on some builds and substitute availability. Once the branch has been merged, the issue should be closed and the branch deleted. @node Debbugs User Interfaces @subsection Debbugs User Interfaces @subsubsection Web interface @cindex mumi, web interface for issues A web interface (actually @emph{two} web interfaces!) are available to browse issues: @itemize @item @url{https://issues.guix.gnu.org} provides a pleasant interface powered by mumi@footnote{Mumi is a nice piece of software written in Guile, and you can help! See @url{https://git.savannah.gnu.org/cgit/guix/mumi.git}.} to browse bug reports and patches, and to participate in discussions; mumi also has a command-line interface as we will see below; @item @url{https://bugs.gnu.org/guix} lists bug reports; @item @url{https://bugs.gnu.org/guix-patches} lists patch submissions. @end itemize To view discussions related to issue number @var{n}, go to @indicateurl{https://issues.guix.gnu.org/@var{n}} or @indicateurl{https://bugs.gnu.org/@var{n}}. @subsubsection Command-Line Interface @cindex mumi command-line interface @cindex mumi am @cindex mumi compose @cindex mumi send-email @cindex mumi www Mumi also comes with a command-line interface that can be used to search existing issues, open new issues, compose replies, apply and send patches. You do not need to use Emacs to use the mumi command-line client. You interact with it only on the command-line. To use the mumi command-line interface, navigate to a local clone of the Guix git repository, and drop into a shell with mumi, git and git:send-email installed. @example $ cd guix ~/guix$ guix shell mumi git git:send-email @end example To search for issues, say all open issues about "zig", run @example ~/guix [env]$ mumi search zig is:open #60889 Add zig-build-system opened on 17 Jan 17:37 Z by Ekaitz Zarraga #61036 [PATCH 0/3] Update zig to 0.10.1 opened on 24 Jan 09:42 Z by Efraim Flashner #39136 [PATCH] gnu: services: Add endlessh. opened on 14 Jan 2020 21:21 by Nicol? Balzarotti #60424 [PATCH] gnu: Add python-online-judge-tools opened on 30 Dec 2022 07:03 by gemmaro #45601 [PATCH 0/6] vlang 0.2 update opened on 1 Jan 2021 19:23 by Ryan Prior @end example Pick an issue and make it the "current" issue. @example ~/guix [env]$ mumi current 61036 #61036 [PATCH 0/3] Update zig to 0.10.1 opened on 24 Jan 09:42 Z by Efraim Flashner @end example Once an issue is the current issue, you can open the issue in a web browser, compose replies, apply patches, send patches, etc. with short succinct commands. Open the issue in your web browser using @example ~/guix [env]$ mumi www @end example Compose a reply using @example ~/guix [env]$ mumi compose @end example Compose a reply and close the issue using @example ~/guix [env]$ mumi compose --close @end example @command{mumi compose} opens your mail client by passing @samp{mailto:} URIs to @command{xdg-open}. So, you need to have @command{xdg-open} set up to open your mail client correctly. Apply the latest patchset from the issue using @example ~/guix [env]$ mumi am @end example You may also apply a patchset of a specific version (say, v3) using @example ~/guix [env]$ mumi am v3 @end example Or, you may apply a patch from a specific e-mail message. For example, to apply the patch from the 4th message (message index starts from 0), run @example ~/guix [env]$ mumi am @@4 @end example @command{mumi am} is a wrapper around @command{git am}. You can pass @command{git am} arguments to it after a @samp{--}. For example, to add a Signed-off-by trailer, run @example ~/guix [env]$ mumi am -- -s @end example Create and send patches to the issue using @example ~/guix [env]$ git format-patch origin/master ~/guix [env]$ mumi send-email foo.patch bar.patch @end example Note that you do not have to pass in @samp{--to} or @samp{--cc} arguments to @command{git format-patch}. @command{mumi send-email} will put them in correctly when sending the patches. To open a new issue, run @example ~/guix [env]$ mumi new @end example and send an email (using @command{mumi compose}) or patches (using @command{mumi send-email}). @command{mumi send-email} is really a wrapper around @command{git send-email} that automates away all the nitty-gritty of sending patches. It uses the current issue state to automatically figure out the correct @samp{To} address to send to, other participants to @samp{Cc}, headers to add, etc. Also note that, unlike @command{git send-email}, @command{mumi send-email} works perfectly well with single and multiple patches alike. It automates away the debbugs dance of sending the first patch, waiting for a response from debbugs and sending the remaining patches. It does so by sending the first patch, polling the server for a response, and then sending the remaining patches. This polling can unfortunately take a few minutes. So, please be patient. @subsubsection Emacs Interface If you use Emacs, you may find it more convenient to interact with issues using @file{debbugs.el}, which you can install with: @example guix install emacs-debbugs @end example For example, to list all open issues on @code{guix-patches}, hit: @example @kbd{C-u} @kbd{M-x} debbugs-gnu @kbd{RET} @kbd{RET} guix-patches @kbd{RET} n y @end example For a more convenient (shorter) way to access both the bugs and patches submissions, you may want to configure the @code{debbugs-gnu-default-packages} and @code{debbugs-gnu-default-severities} Emacs variables (@pxref{Viewing Bugs within Emacs}). To search for bugs, @samp{@kbd{M-x} debbugs-gnu-guix-search} can be used. @xref{Top,,, debbugs-ug, Debbugs User Guide}, for more information on this nifty tool! @node Debbugs Usertags @subsection Debbugs Usertags @cindex usertags, for debbugs @cindex Debbugs usertags Debbugs provides a feature called @dfn{usertags} that allows any user to tag any bug with an arbitrary label. Bugs can be searched by usertag, so this is a handy way to organize bugs@footnote{The list of usertags is public information, and anyone can modify any user's list of usertags, so keep that in mind if you choose to use this feature.}. If you use Emacs Debbugs, the entry-point to consult existing usertags is the @samp{C-u M-x debbugs-gnu-usertags} procedure. To set a usertag, press @samp{C} while consulting a bug within the *Guix-Patches* buffer opened with @samp{C-u M-x debbugs-gnu-bugs} buffer, then select @code{usertag} and follow the instructions. For example, to view all the bug reports (or patches, in the case of @code{guix-patches}) tagged with the usertag @code{powerpc64le-linux} for the user @code{guix}, open a URL like the following in a web browser: @url{https://debbugs.gnu.org/cgi-bin/pkgreport.cgi?tag=powerpc64le-linux;users=guix}. For more information on how to use usertags, please refer to the documentation for Debbugs or the documentation for whatever tool you use to interact with Debbugs. In Guix, we are experimenting with usertags to keep track of architecture-specific issues, as well as reviewed ones. To facilitate collaboration, all our usertags are associated with the single user @code{guix}. The following usertags currently exist for that user: @table @code @item powerpc64le-linux The purpose of this usertag is to make it easy to find the issues that matter most for the @code{powerpc64le-linux} system type. Please assign this usertag to bugs or patches that affect @code{powerpc64le-linux} but not other system types. In addition, you may use it to identify issues that for some reason are particularly important for the @code{powerpc64le-linux} system type, even if the issue affects other system types, too. @item reproducibility For issues related to reproducibility. For example, it would be appropriate to assign this usertag to a bug report for a package that fails to build reproducibly. @item reviewed-looks-good You have reviewed the series and it looks good to you (LGTM). @end table If you're a committer and you want to add a usertag, just start using it with the @code{guix} user. If the usertag proves useful to you, consider updating this section of the manual so that others will know what your usertag means. @node Cuirass Build Notifications @subsection Cuirass Build Notifications @cindex build event notifications, RSS feed @cindex notifications, build events Cuirass includes @acronym{RSS, Really Simple Syndication} feeds as one of its features (@pxref{Notifications,,,cuirass}). Since @url{https://ci.guix.gnu.org/, Berlin} runs an instance of Cuirass, this feature can be used to keep track of recently broken or fixed packages caused by changes pushed to the Guix git repository. Any RSS client can be used. A good one, included with Emacs, is @xref{Gnus,,,gnus}. To register the feed, copy its URL, then from the main Gnus buffer, @samp{*Group*}, do the following: @cindex Gnus, configuration to read CI RSS feeds @cindex RSS feeds, Gnus configuration @example @kbd{G R} https://ci.guix.gnu.org/events/rss/?specification=master RET Guix CI - master RET Build events for specification master. RET @end example @noindent Then, back at the @samp{*Group*} buffer, press @kbd{s} to save the newly added RSS group. As for any other Gnus group, you can update its content by pressing the @kbd{g} key. You should now receive notifications that read like: @example . [ ?: Cuirass ] Build tree-sitter-meson.aarch64-linux on master is fixed. . [ ?: Cuirass ] Build rust-pbkdf2.aarch64-linux on master is fixed. . [ ?: Cuirass ] Build rust-pbkdf2.x86_64-linux on master is fixed. @end example @noindent where each RSS entry contains a link to the Cuirass build details page of the associated build. @node Commit Access @section Commit Access @cindex commit access, for developers Everyone can contribute to Guix without having commit access (@pxref{Submitting Patches}). However, for frequent contributors, having write access to the repository can be convenient. As a rule of thumb, a contributor should have accumulated fifty (50) reviewed commits to be considered as a committer and have sustained their activity in the project for at least 6 months. This ensures enough interactions with the contributor, which is essential for mentoring and assessing whether they are ready to become a committer. Commit access should not be thought of as a ``badge of honor'' but rather as a responsibility a contributor is willing to take to help the project. It is expected from all contributors, and even more so from committers, to help build consensus and make decisions based on consensus. By using consensus, we are committed to finding solutions that everyone can live with. It implies that no decision is made against significant concerns and these concerns are actively resolved with proposals that work for everyone. A contributor (which may or may not have commit access) wishing to block a proposal bears a special responsibility for finding alternatives, proposing ideas/code or explain the rationale for the status quo to resolve the deadlock. To learn what consensus decision making means and understand its finer details, you are encouraged to read @url{https://www.seedsforchange.org.uk/consensus}. The following sections explain how to get commit access, how to be ready to push commits, and the policies and community expectations for commits pushed upstream. @subsection Applying for Commit Access When you deem it necessary, consider applying for commit access by following these steps: @enumerate @item Find three committers who would vouch for you. You can view the list of committers at @url{https://savannah.gnu.org/project/memberlist.php?group=guix}. Each of them should email a statement to @email{guix-maintainers@@gnu.org} (a private alias for the collective of maintainers), signed with their OpenPGP key. Committers are expected to have had some interactions with you as a contributor and to be able to judge whether you are sufficiently familiar with the project's practices. It is @emph{not} a judgment on the value of your work, so a refusal should rather be interpreted as ``let's try again later''. @item Send @email{guix-maintainers@@gnu.org} a message stating your intent, listing the three committers who support your application, signed with the OpenPGP key you will use to sign commits, and giving its fingerprint (see below). See @uref{https://emailselfdefense.fsf.org/en/}, for an introduction to public-key cryptography with GnuPG. @c See . Set up GnuPG such that it never uses the SHA1 hash algorithm for digital signatures, which is known to be unsafe since 2019, for instance by adding the following line to @file{~/.gnupg/gpg.conf} (@pxref{GPG Esoteric Options,,, gnupg, The GNU Privacy Guard Manual}): @example digest-algo sha512 @end example @item Maintainers ultimately decide whether to grant you commit access, usually following your referrals' recommendation. @item @cindex OpenPGP, signed commits If and once you've been given access, please send a message to @email{guix-devel@@gnu.org} to say so, again signed with the OpenPGP key you will use to sign commits (do that before pushing your first commit). That way, everyone can notice and ensure you control that OpenPGP key. @quotation Important Before you can push for the first time, maintainers must: @enumerate @item add your OpenPGP key to the @code{keyring} branch; @item add your OpenPGP fingerprint to the @file{.guix-authorizations} file of the branch(es) you will commit to. @end enumerate @end quotation @item Make sure to read the rest of this section and... profit! @end enumerate @quotation Note Maintainers are happy to give commit access to people who have been contributing for some time and have a track record---don't be shy and don't underestimate your work! However, note that the project is working towards a more automated patch review and merging system, which, as a consequence, may lead us to have fewer people with commit access to the main repository. Stay tuned! @end quotation All commits that are pushed to the central repository on Savannah must be signed with an OpenPGP key, and the public key should be uploaded to your user account on Savannah and to public key servers, such as @code{keys.openpgp.org}. To configure Git to automatically sign commits, run: @example git config commit.gpgsign true # Substitute the fingerprint of your public PGP key. git config user.signingkey CABBA6EA1DC0FF33 @end example To check that commits are signed with correct key, use: @example guix git authenticate @end example @xref{Building from Git} for running the first authentication of a Guix checkout. To avoid accidentally pushing unsigned or signed with the wrong key commits to Savannah, make sure to configure Git according to @xref{Configuring Git}. @subsection Commit Policy If you get commit access, please make sure to follow the policy below (discussions of the policy can take place on @email{guix-devel@@gnu.org}). Ensure you're aware of how the changes should be handled (@pxref{Managing Patches and Branches}) prior to being pushed to the repository, especially for the @code{master} branch. If you're committing and pushing your own changes, try and wait at least one week (two weeks for more significant changes) after you send them for review. After this, if no one else is available to review them and if you're confident about the changes, it's OK to commit. When pushing a commit on behalf of somebody else, please add a @code{Signed-off-by} line at the end of the commit log message---e.g., with @command{git am --signoff}. This improves tracking of who did what. When adding channel news entries (@pxref{Channels, Writing Channel News}), make sure they are well-formed by running the following command right before pushing: @example make check-channel-news @end example @subsection Addressing Issues Peer review (@pxref{Submitting Patches}) and tools such as @command{guix lint} (@pxref{Invoking guix lint}) and the test suite (@pxref{Running the Test Suite}) should catch issues before they are pushed. Yet, commits that ``break'' functionality might occasionally go through. When that happens, there are two priorities: mitigating the impact, and understanding what happened to reduce the chance of similar incidents in the future. The responsibility for both these things primarily lies with those involved, but like everything this is a group effort. Some issues can directly affect all users---for instance because they make @command{guix pull} fail or break core functionality, because they break major packages (at build time or run time), or because they introduce known security vulnerabilities. @cindex reverting commits The people involved in authoring, reviewing, and pushing such commit(s) should be at the forefront to mitigate their impact in a timely fashion: by pushing a followup commit to fix it (if possible), or by reverting it to leave time to come up with a proper fix, and by communicating with other developers about the problem. If these persons are unavailable to address the issue in time, other committers are entitled to revert the commit(s), explaining in the commit log and on the mailing list what the problem was, with the goal of leaving time to the original committer, reviewer(s), and author(s) to propose a way forward. Once the problem has been dealt with, it is the responsibility of those involved to make sure the situation is understood. If you are working to understand what happened, focus on gathering information and avoid assigning any blame. Do ask those involved to describe what happened, do not ask them to explain the situation---this would implicitly blame them, which is unhelpful. Accountability comes from a consensus about the problem, learning from it and improving processes so that it's less likely to reoccur. @subsection Commit Revocation In order to reduce the possibility of mistakes, committers will have their Savannah account removed from the Guix Savannah project and their key removed from @file{.guix-authorizations} after 12 months of inactivity; they can ask to regain commit access by emailing the maintainers, without going through the vouching process. Maintainers@footnote{See @uref{https://guix.gnu.org/en/about} for the current list of maintainers. You can email them privately at @email{guix-maintainers@@gnu.org}.} may also revoke an individual's commit rights, as a last resort, if cooperation with the rest of the community has caused too much friction---even within the bounds of the project's code of conduct (@pxref{Contributing}). They would only do so after public or private discussion with the individual and a clear notice. Examples of behavior that hinders cooperation and could lead to such a decision include: @itemize @item repeated violation of the commit policy stated above; @item repeated failure to take peer criticism into account; @item breaching trust through a series of grave incidents. @end itemize When maintainers resort to such a decision, they notify developers on @email{guix-devel@@gnu.org}; inquiries may be sent to @email{guix-maintainers@@gnu.org}. Depending on the situation, the individual may still be welcome to contribute. @subsection Helping Out One last thing: the project keeps moving forward because committers not only push their own awesome changes, but also offer some of their time @emph{reviewing} and pushing other people's changes. As a committer, you're welcome to use your expertise and commit rights to help other contributors, too! @node Reviewing the Work of Others @section Reviewing the Work of Others Perhaps the biggest action you can do to help GNU Guix grow as a project is to review the work contributed by others. You do not need to be a committer to do so; applying, reading the source, building, linting and running other people's series and sharing your comments about your experience will give some confidence to committers. Basically, you must ensure the check list found in the @ref{Submitting Patches} section has been correctly followed. A reviewed patch series should give the best chances for the proposed change to be merged faster, so if a change you would like to see merged hasn't yet been reviewed, this is the most appropriate thing to do! @cindex reviewing, guidelines Review comments should be unambiguous; be as clear and explicit as you can about what you think should be changed, ensuring the author can take action on it. Please try to keep the following guidelines in mind during review: @enumerate @item @emph{Be clear and explicit about changes you are suggesting}, ensuring the author can take action on it. In particular, it is a good idea to explicitly ask for new revisions when you want it. @item @emph{Remain focused: do not change the scope of the work being reviewed.} For example, if the contribution touches code that follows a pattern deemed unwieldy, it would be unfair to ask the submitter to fix all occurrences of that pattern in the code; to put it simply, if a problem unrelated to the patch at hand was already there, do not ask the submitter to fix it. @item @emph{Ensure progress.} As they respond to review, submitters may submit new revisions of their changes; avoid requesting changes that you did not request in the previous round of comments. Overall, the submitter should get a clear sense of progress; the number of items open for discussion should clearly decrease over time. @item @emph{Aim for finalization.} Reviewing code is time-consuming. Your goal as a reviewer is to put the process on a clear path towards integration, possibly with agreed-upon changes, or rejection, with a clear and mutually-understood reasoning. Avoid leaving the review process in a lingering state with no clear way out. @item @emph{Review is a discussion.} The submitter's and reviewer's views on how to achieve a particular change may not always be aligned. To lead the discussion, remain focused, ensure progress and aim for finalization, spending time proportional to the stakes@footnote{The tendency to discuss minute details at length is often referred to as ``bikeshedding'', where much time is spent discussing each one's preference for the color of the shed at the expense of progress made on the project to keep bikes dry.}. As a reviewer, try hard to explain the rationale for suggestions you make, and to understand and take into account the submitter's motivation for doing things in a certain way. @end enumerate @cindex LGTM, Looks Good To Me @cindex review tags @cindex Reviewed-by, git trailer When you deem the proposed change adequate and ready for inclusion within Guix, the following well understood/codified @samp{Reviewed-by:@tie{}Your@tie{}Name@tie{}} @footnote{The @samp{Reviewed-by} Git trailer is used by other projects such as Linux, and is understood by third-party tools such as the @samp{b4 am} sub-command, which is able to retrieve the complete submission email thread from a public-inbox instance and add the Git trailers found in replies to the commit patches.} line should be used to sign off as a reviewer, meaning you have reviewed the change and that it looks good to you: @itemize @item If the @emph{whole} series (containing multiple commits) looks good to you, reply with @samp{Reviewed-by:@tie{}Your@tie{}Name@tie{}} to the cover page if it has one, or to the last patch of the series otherwise, adding another @samp{(for the whole series)} comment on the line below to explicit this fact. @item If you instead want to mark a @emph{single commit} as reviewed (but not the whole series), simply reply with @samp{Reviewed-by:@tie{}Your@tie{}Name@tie{}} to that commit message. @end itemize If you are not a committer, you can help others find a @emph{series} you have reviewed more easily by adding a @code{reviewed-looks-good} usertag for the @code{guix} user (@pxref{Debbugs Usertags}). @node Updating the Guix Package @section Updating the Guix Package @cindex update-guix-package, updating the guix package It is sometimes desirable to update the @code{guix} package itself (the package defined in @code{(gnu packages package-management)}), for example to make new daemon features available for use by the @code{guix-service-type} service type. In order to simplify this task, the following command can be used: @example make update-guix-package @end example The @code{update-guix-package} make target will use the last known @emph{commit} corresponding to @code{HEAD} in your Guix checkout, compute the hash of the Guix sources corresponding to that commit and update the @code{commit}, @code{revision} and hash of the @code{guix} package definition. To validate that the updated @code{guix} package hashes are correct and that it can be built successfully, the following command can be run from the directory of your Guix checkout: @example ./pre-inst-env guix build guix @end example To guard against accidentally updating the @code{guix} package to a commit that others can't refer to, a check is made that the commit used has already been pushed to the Savannah-hosted Guix git repository. This check can be disabled, @emph{at your own peril}, by setting the @code{GUIX_ALLOW_ME_TO_USE_PRIVATE_COMMIT} environment variable. When this variable is set, the updated package source is also added to the store. This is used as part of the release process of Guix. @cindex documentation @node Writing Documentation @section Writing Documentation Guix is documented using the Texinfo system. If you are not yet familiar with it, we accept contributions for documentation in most formats. That includes plain text, Markdown, Org, etc. Documentation contributions can be sent to @email{guix-patches@@gnu.org}. Prepend @samp{[DOCUMENTATION]} to the subject. When you need to make more than a simple addition to the documentation, we prefer that you send a proper patch as opposed to sending an email as described above. @xref{Submitting Patches} for more information on how to send your patches. To modify the documentation, you need to edit @file{doc/guix.texi} and @file{doc/contributing.texi} (which contains this documentation section), or @file{doc/guix-cookbook.texi} for the cookbook. If you compiled the Guix repository before, you will have many more @file{.texi} files that are translations of these documents. Do not modify them, the translation is managed through @uref{https://translate.fedoraproject.org/projects/guix, Weblate}. @xref{Translating Guix} for more information. To render documentation, you must first make sure that you ran @command{./configure} in your source tree (@pxref{Running Guix Before It Is Installed}). After that you can run one of the following commands: @itemize @item @samp{make doc/guix.info} to compile the Info manual. You can check it with @command{info doc/guix.info}. @item @samp{make doc/guix.html} to compile the HTML version. You can point your browser to the relevant file in the @file{doc/guix.html} directory. @item @samp{make doc/guix-cookbook.info} for the cookbook Info manual. @item @samp{make doc/guix-cookbook.html} for the cookbook HTML version. @end itemize @cindex translation @cindex l10n @cindex i18n @cindex native language support @node Translating Guix @section Translating Guix Writing code and packages is not the only way to provide a meaningful contribution to Guix. Translating to a language you speak is another example of a valuable contribution you can make. This section is designed to describe the translation process. It gives you advice on how you can get involved, what can be translated, what mistakes you should avoid and what we can do to help you! Guix is a big project that has multiple components that can be translated. We coordinate the translation effort on a @uref{https://translate.fedoraproject.org/projects/guix/,Weblate instance} hosted by our friends at Fedora. You will need an account to submit translations. Some of the software packaged in Guix also contain translations. We do not host a translation platform for them. If you want to translate a package provided by Guix, you should contact their developers or find the information on their website. As an example, you can find the homepage of the @code{hello} package by typing @code{guix show hello}. On the ``homepage'' line, you will see @url{https://www.gnu.org/software/hello/} as the homepage. Many GNU and non-GNU packages can be translated on the @uref{https://translationproject.org,Translation Project}. Some projects with multiple components have their own platform. For instance, GNOME has its own platform, @uref{https://l10n.gnome.org/,Damned Lies}. Guix has five components hosted on Weblate. @itemize @item @code{guix} contains all the strings from the Guix software (the guided system installer, the package manager, etc), excluding packages. @item @code{packages} contains the synopsis (single-sentence description of a package) and description (longer description) of packages in Guix. @item @code{website} contains the official Guix website, except for blog posts and multimedia content. @item @code{documentation-manual} corresponds to this manual. @item @code{documentation-cookbook} is the component for the cookbook. @end itemize @subsubheading General Directions Once you get an account, you should be able to select a component from @uref{https://translate.fedoraproject.org/projects/guix/,the guix project}, and select a language. If your language does not appear in the list, go to the bottom and click on the ``Start new translation'' button. Select the language you want to translate to from the list, to start your new translation. Like lots of other free software packages, Guix uses @uref{https://www.gnu.org/software/gettext,GNU Gettext} for its translations, with which translatable strings are extracted from the source code to so-called PO files. Even though PO files are text files, changes should not be made with a text editor but with PO editing software. Weblate integrates PO editing functionality. Alternatively, translators can use any of various free-software tools for filling in translations, of which @uref{https://poedit.net/,Poedit} is one example, and (after logging in) @uref{https://docs.weblate.org/en/latest/user/files.html,upload} the changed file. There is also a special @uref{https://www.emacswiki.org/emacs/PoMode,PO editing mode} for users of GNU Emacs. Over time translators find out what software they are happy with and what features they need. On Weblate, you will find various links to the editor, that will show various subsets (or all) of the strings. Have a look around and at the @uref{https://docs.weblate.org/en/latest/,documentation} to familiarize yourself with the platform. @subsubheading Translation Components In this section, we provide more detailed guidance on the translation process, as well as details on what you should or should not do. When in doubt, please contact us, we will be happy to help! @table @asis @item guix Guix is written in the Guile programming language, and some strings contain special formatting that is interpreted by Guile. These special formatting should be highlighted by Weblate. They start with @code{~} followed by one or more characters. When printing the string, Guile replaces the special formatting symbols with actual values. For instance, the string @samp{ambiguous package specification `~a'} would be substituted to contain said package specification instead of @code{~a}. To properly translate this string, you must keep the formatting code in your translation, although you can place it where it makes sense in your language. For instance, the French translation says @samp{spécification du paquet « ~a » ambiguë} because the adjective needs to be placed in the end of the sentence. If there are multiple formatting symbols, make sure to respect the order. Guile does not know in which order you intended the string to be read, so it will substitute the symbols in the same order as the English sentence. As an example, you cannot translate @samp{package '~a' has been superseded by '~a'} by @samp{'~a' superseeds package '~a'}, because the meaning would be reversed. If @var{foo} is superseded by @var{bar}, the translation would read @samp{'foo' superseeds package 'bar'}. To work around this problem, it is possible to use more advanced formatting to select a given piece of data, instead of following the default English order. @xref{Formatted Output,,, guile, GNU Guile Reference Manual}, for more information on formatting in Guile. @item packages Package descriptions occasionally contain Texinfo markup (@pxref{Synopses and Descriptions}). Texinfo markup looks like @samp{@@code@{rm -rf@}}, @samp{@@emph@{important@}}, etc. When translating, please leave markup as is. The characters after ``@@'' form the name of the markup, and the text between ``@{'' and ``@}'' is its content. In general, you should not translate the content of markup like @code{@@code}, as it contains literal code that do not change with language. You can translate the content of formatting markup such as @code{@@emph}, @code{@@i}, @code{@@itemize}, @code{@@item}. However, do not translate the name of the markup, or it will not be recognized. Do not translate the word after @code{@@end}, it is the name of the markup that is closed at this position (e.g.@: @code{@@itemize ... @@end itemize}). @item documentation-manual and documentation-cookbook The first step to ensure a successful translation of the manual is to find and translate the following strings @emph{first}: @itemize @item @code{version.texi}: Translate this string as @code{version-xx.texi}, where @code{xx} is your language code (the one shown in the URL on weblate). @item @code{contributing.texi}: Translate this string as @code{contributing.xx.texi}, where @code{xx} is the same language code. @item @code{Top}: Do not translate this string, it is important for Texinfo. If you translate it, the document will be empty (missing a Top node). Please look for it, and register @code{Top} as its translation. @end itemize Translating these strings first ensure we can include your translation in the guix repository without breaking the make process or the @command{guix pull} machinery. The manual and the cookbook both use Texinfo. As for @code{packages}, please keep Texinfo markup as is. There are more possible markup types in the manual than in the package descriptions. In general, do not translate the content of @code{@@code}, @code{@@file}, @code{@@var}, @code{@@value}, etc. You should translate the content of formatting markup such as @code{@@emph}, @code{@@i}, etc. The manual contains sections that can be referred to by name by @code{@@ref}, @code{@@xref} and @code{@@pxref}. We have a mechanism in place so you do not have to translate their content. If you keep the English title, we will automatically replace it with your translation of that title. This ensures that Texinfo will always be able to find the node. If you decide to change the translation of the title, the references will automatically be updated and you will not have to update them all yourself. When translating references from the cookbook to the manual, you need to replace the name of the manual and the name of the section. For instance, to translate @code{@@pxref@{Defining Packages,,, guix, GNU Guix Reference Manual@}}, you would replace @code{Defining Packages} with the title of that section in the translated manual @emph{only} if that title is translated. If the title is not translated in your language yet, do not translate it here, or the link will be broken. Replace @code{guix} with @code{guix.xx} where @code{xx} is your language code. @code{GNU Guix Reference Manual} is the text of the link. You can translate it however you wish. @item website The website pages are written using SXML, an s-expression version of HTML, the basic language of the web. We have a process to extract translatable strings from the source, and replace complex s-expressions with a more familiar XML markup, where each markup is numbered. Translators can arbitrarily change the ordering, as in the following example. @example #. TRANSLATORS: Defining Packages is a section name #. in the English (en) manual. #: apps/base/templates/about.scm:64 msgid "Packages are <1>defined<1.1>en<1.2>Defining-Packages.html as native <2>Guile modules." msgstr "Pakete werden als reine <2>Guile-Module <1>definiert<1.1>de<1.2>Pakete-definieren.html." @end example Note that you need to include the same markups. You cannot skip any. @end table In case you make a mistake, the component might fail to build properly with your language, or even make guix pull fail. To prevent that, we have a process in place to check the content of the files before pushing to our repository. We will not be able to update the translation for your language in Guix, so we will notify you (through weblate and/or by email) so you get a chance to fix the issue. @subsubheading Outside of Weblate Currently, some parts of Guix cannot be translated on Weblate, help wanted! @itemize @item @command{guix pull} news can be translated in @file{news.scm}, but is not available from Weblate. If you want to provide a translation, you can prepare a patch as described above, or simply send us your translation with the name of the news entry you translated and your language. @xref{Writing Channel News}, for more information about channel news. @item Guix blog posts cannot currently be translated. @item The installer script (for foreign distributions) is entirely in English. @item Some of the libraries Guix uses cannot be translated or are translated outside of the Guix project. Guile itself is not internationalized. @item Other manuals linked from this manual or the cookbook might not be translated. @end itemize @subsubheading Conditions for Inclusion There are no conditions for adding new translations of the @code{guix} and @code{guix-packages} components, other than they need at least one translated string. New languages will be added to Guix as soon as possible. The files may be removed if they fall out of sync and have no more translated strings. Given that the web site is dedicated to new users, we want its translation to be as complete as possible before we include it in the language menu. For a new language to be included, it needs to reach at least 80% completion. When a language is included, it may be removed in the future if it stays out of sync and falls below 60% completion. The manual and cookbook are automatically added in the default compilation target. Every time we synchronize translations, developers need to recompile all the translated manuals and cookbooks. This is useless for what is essentially the English manual or cookbook. Therefore, we will only include a new language when it reaches 10% completion in the component. When a language is included, it may be removed in the future if it stays out of sync and falls below 5% completion. @subsubheading Translation Infrastructure Weblate is backed by a git repository from which it discovers new strings to translate and pushes new and updated translations. Normally, it would be enough to give it commit access to our repositories. However, we decided to use a separate repository for two reasons. First, we would have to give Weblate commit access and authorize its signing key, but we do not trust it in the same way we trust guix developers, especially since we do not manage the instance ourselves. Second, if translators mess something up, it can break the generation of the website and/or guix pull for all our users, independently of their language. For these reasons, we use a dedicated repository to host translations, and we synchronize it with our guix and artworks repositories after checking no issue was introduced in the translation. Developers can download the latest PO files from weblate in the Guix repository by running the @command{make download-po} command. It will automatically download the latest files from weblate, reformat them to a canonical form, and check they do not contain issues. The manual needs to be built again to check for additional issues that might crash Texinfo. Before pushing new translation files, developers should add them to the make machinery so the translations are actually available. The process differs for the various components. @itemize @item New po files for the @code{guix} and @code{packages} components must be registered by adding the new language to @file{po/guix/LINGUAS} or @file{po/packages/LINGUAS}. @item New po files for the @code{documentation-manual} component must be registered by adding the file name to @code{DOC_PO_FILES} in @file{po/doc/local.mk}, the generated @file{%D%/guix.xx.texi} manual to @code{info_TEXINFOS} in @file{doc/local.mk} and the generated @file{%D%/guix.xx.texi} and @file{%D%/contributing.xx.texi} to @code{TRANSLATED_INFO} also in @file{doc/local.mk}. @item New po files for the @code{documentation-cookbook} component must be registered by adding the file name to @code{DOC_COOKBOOK_PO_FILES} in @file{po/doc/local.mk}, the generated @file{%D%/guix-cookbook.xx.texi} manual to @code{info_TEXINFOS} in @file{doc/local.mk} and the generated @file{%D%/guix-cookbook.xx.texi} to @code{TRANSLATED_INFO} also in @file{doc/local.mk}. @item New po files for the @code{website} component must be added to the @code{guix-artwork} repository, in @file{website/po/}. @file{website/po/LINGUAS} and @file{website/po/ietf-tags.scm} must be updated accordingly (see @file{website/i18n-howto.txt} for more information on the process). @end itemize