Clang attempts to guess file names based on the OS and distro (yes!),
but unfortunately, that doesn't work for us.

This patch makes it easy to insert libc's $libdir so that Clang passes the
correct absolute file name of crt1.o etc. to 'ld'.  It also disables all
the distro-specific stuff and removes the hard-coded FHS directory names
to make sure Clang also works on non-GuixSD systems.

--- cfe-3.6.0.src/lib/Driver/ToolChains.cpp	2015-02-18 22:03:07.000000000 +0100
+++ cfe-3.6.0.src/lib/Driver/ToolChains.cpp	2015-06-19 16:37:20.459701044 +0200
@@ -2931,6 +2931,9 @@ Linux::Linux(const Driver &D, const llvm
 
   Linker = GetLinkerPath();
 
+  // Comment out the distro-specific tweaks so that they don't bite when
+  // using Guix on a foreign distro.
+#if 0
   Distro Distro = DetectDistro(Arch);
 
   if (IsOpenSUSE(Distro) || IsUbuntu(Distro)) {
@@ -2973,6 +2976,7 @@ Linux::Linux(const Driver &D, const llvm
 
   if (IsOpenSUSE(Distro))
     ExtraOpts.push_back("--enable-new-dtags");
+#endif
 
   // The selection of paths to try here is designed to match the patterns which
   // the GCC driver itself uses, as this is part of the GCC-compatible driver.
@@ -3043,14 +3047,12 @@ Linux::Linux(const Driver &D, const llvm
     addPathIfExists(D.Dir + "/../" + OSLibDir, Paths);
   }
 
-  addPathIfExists(SysRoot + "/lib/" + MultiarchTriple, Paths);
-  addPathIfExists(SysRoot + "/lib/../" + OSLibDir, Paths);
-  addPathIfExists(SysRoot + "/usr/lib/" + MultiarchTriple, Paths);
-  addPathIfExists(SysRoot + "/usr/lib/../" + OSLibDir, Paths);
-
   // Try walking via the GCC triple path in case of biarch or multiarch GCC
   // installations with strange symlinks.
   if (GCCInstallation.isValid()) {
+    // The following code would end up adding things like
+    // "/usr/lib/x86_64-unknown-linux-gnu/../../lib64" to the search path.
+#if 0
     addPathIfExists(SysRoot + "/usr/lib/" + GCCInstallation.getTriple().str() +
                     "/../../" + OSLibDir, Paths);
 
@@ -3060,6 +3062,7 @@ Linux::Linux(const Driver &D, const llvm
       addPathIfExists(GCCInstallation.getInstallPath() +
                       BiarchSibling.gccSuffix(), Paths);
     }
+#endif
 
     // See comments above on the multilib variant for details of why this is
     // included even from outside the sysroot.
@@ -3083,8 +3086,9 @@ Linux::Linux(const Driver &D, const llvm
   if (StringRef(D.Dir).startswith(SysRoot))
     addPathIfExists(D.Dir + "/../lib", Paths);
 
-  addPathIfExists(SysRoot + "/lib", Paths);
-  addPathIfExists(SysRoot + "/usr/lib", Paths);
+  // Add libc's lib/ directory to the search path, so that crt1.o, crti.o,
+  // and friends can be found.
+  addPathIfExists("@GLIBC_LIBDIR@", Paths);
 }
 
 bool Linux::HasNativeLLVMSupport() const {
d by Guile-JSON 3.5.0.

* tests/crate.scm (test-foo-dependencies)
(test-root-dependencies, test-intermediate-1-dependencies)
(test-intermediate-2-dependencies): Remove trailing commas.
* tests/gem.scm (test-bar-json): Likewise.
* tests/pypi.scm (test-json): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-02-05 16:18:58 +0100'>2020-02-05</span></td><td><a href='/guix/commit/tests/gem.scm?id=c24fe4a52057ea3390faf59fd672a617eff34aea'>import: gem: Deal with unavailable licensing info.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/39404&gt;.
Reported by Seth &lt;lee.seth@tuta.io&gt;.

* guix/import/gem.scm (&lt;gem&gt;)[licenses]: Adjust for non-vector
licenses.
* tests/gem.scm (test-bar-json): Change "licenses" to 'null'.
("gem-recursive-import"): Adjust accordingly.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-12-11 12:13:03 +0100'>2019-12-11</span></td><td><a href='/guix/commit/tests/gem.scm?id=70a8e13277d4a44b89dd9ee2290b98105f0235f1'>import: utils: 'recursive-import' returns a list rather than a stream.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/utils.scm (recursive-import): Remove 'list-&gt;stream' call.
* guix/scripts/import/cran.scm (guix-import-cran): Remove 'stream-&gt;list'
call.
* guix/scripts/import/crate.scm (guix-import-crate): Likewise.
* guix/scripts/import/elpa.scm (guix-import-elpa): Likewise.
* guix/scripts/import/gem.scm (guix-import-gem): Likewise.
* guix/scripts/import/hackage.scm (guix-import-hackage): Likewise.
* guix/scripts/import/opam.scm (guix-import-opam): Likewise.
* guix/scripts/import/pypi.scm (guix-import-pypi): Likewise.
* guix/scripts/import/stackage.scm (guix-import-stackage): Likewise.
* tests/gem.scm ("gem-recursive-import"): Likewise.
* tests/import-utils.scm ("recursive-import"): Likewise.

Co-authored-by: Brian Leung &lt;bkleung89@gmail.com&gt;
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-12-11 12:12:58 +0100'>2019-12-11</span></td><td><a href='/guix/commit/tests/gem.scm?id=ddd59159004ca73c9449a27945116ff5069c3743'>import: utils: 'recursive-import' returns packages in topological order.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/utils.scm (topological-sort): New procedure.
(recursive-import): Rewrite to use it.
* tests/import-utils.scm ("recursive-import"): New test.
* guix/import/cran.scm (cran-&gt;guix-package): Always return two values.
* guix/scripts/import/cran.scm (guix-import-cran): Remove 'reverse' call
on 'cran-recursive-import' result.
* guix/scripts/import/crate.scm (guix-import-crate): Likewise.
* guix/scripts/import/elpa.scm (guix-import-elpa): Likewise.
* guix/scripts/import/gem.scm (guix-import-gem): Likewise.
* guix/scripts/import/hackage.scm (guix-import-hackage): Likewise.
* guix/scripts/import/opam.scm (guix-import-opam): Likewise.
* guix/scripts/import/pypi.scm (guix-import-pypi): Likewise.
* guix/scripts/import/stackage.scm (guix-import-stackage): Likewise.
* tests/gem.scm ("gem-recursive-import"): Change the order of package
expressions accordingly.
</span></span></td><td>Ludovic Courtès</td></tr>