Versioneer does not work in the Guix build container because:

* VCS information is unavailable
* the build directory does not have the supported "$name-$version" format
* as of 0.21, versioneer has no way to override the discovered values

This patch adds support for extracting version from the
'/tmp/guix-build-foo-0.1.drv-0' style directories created by the daemon.

diff --git a/src/from_parentdir.py b/src/from_parentdir.py
index 69ada9a..e0fac8f 100644
--- a/src/from_parentdir.py
+++ b/src/from_parentdir.py
@@ -15,6 +15,21 @@ def versions_from_parentdir(parentdir_prefix, root, verbose):
             return {"version": dirname[len(parentdir_prefix):],
                     "full-revisionid": None,
                     "dirty": False, "error": None, "date": None}
+        # Guix specific patch: try extracting the version from the build
+        # directory.
+        elif dirname.startswith("guix-build-"):
+            delimiter = dirname.rindex(".drv-")
+            name_and_version = dirname[11:delimiter]
+            if name_and_version.startswith(parentdir_prefix):
+                guix_version = name_and_version[len(parentdir_prefix):]
+            elif name_and_version.startswith("python-{}".format(parentdir_prefix)):
+                guix_version = name_and_version[(7 + len(parentdir_prefix)):]
+            else:
+                break
+            return {"version": guix_version,
+                    "full-revisionid": None,
+                    "dirty": False, "error": None, "date": None}
+
         rootdirs.append(root)
         root = os.path.dirname(root)  # up a level
 
ut type='hidden' name='id' value='603407fa0a9b2435b9688d0bb2d099c31f22ec45'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=603407fa0a9b2435b9688d0bb2d099c31f22ec45'>root</a>/<a href='/guix/log/tests?id=603407fa0a9b2435b9688d0bb2d099c31f22ec45'>tests</a>/<a href='/guix/log/tests/import-github.scm?id=603407fa0a9b2435b9688d0bb2d099c31f22ec45'>import-github.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/import-github.scm?id=603407fa0a9b2435b9688d0bb2d099c31f22ec45&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-12-26 17:15:06 +0100'>2022-12-26</span></td><td><a href='/guix/commit/tests/import-github.scm?id=a274a6a1acb99738f02de7b226e6a0d3883ec353'>upstream-updater: Rename record field.</a><span class='msg-avail'>...<span class='msg-tooltip'>The next commits will make the functions, which are currently importing the
latest version of a package, change into importing the latest or a given
version of the package (for those updaters supporting specifying a version).
Thus the name ‘latest‘ is no longer appropriate.

* guix/upstream.scm (upstream-updater) Rename field [latest] to
  [import]. (lookup-updater, package-latest-release) Adjust fieldname
  accordingly.
* guix/gnu-maintenance.scm (%gnu-updater, %gnu-ftp-updater,
  %savannah-updater, %sourceforge-updater, %xorg-updater,
  %kernel.org-updater, %generic-html-updater),
  guix/import/cpan.scm (%cpan-updater),
  guix/import/cran.scm (%cran-updater, %bioconductor-updater),
  guix/import/crate.scm (%crate-updater),
  guix/import/egg.scm (%egg-updater),
  guix/import/elpa.scm (%elpa-updater),
  guix/import/gem.scm (%gem-updater),
  guix/import/git.scm (%generic-git-updater),
  guix/import/github.scm (%github-updater),
  guix/import/gnome.scm (%gnome-updater),
  guix/import/hackage.scm (%hackage-updater),
  guix/import/hexpm.scm (%hexpm-updater),
  guix/import/kde.scm (%kde-updater),
  guix/import/launchpad.scm (%launchpad-updater),
  guix/import/minetest.scm (%minetest-updater),
  guix/import/opam.scm (%opam-updater),
  guix/import/pypi.scm (%pypi-updater),
  guix/import/stackage.scm (%stackage-updater),
  tests/import-github.scm (found-sexp)
  tests/transformations.scm ("options-&gt;transformation, with-latest"):
  Adjust fieldname accordingly.
</span></span></td><td>Hartmut Goebel</td></tr>