The Clar test framework has a bug whereby it skips the parsing phase
on files with mtime=0.

Reported upstream at <https://github.com/vmg/clar/pull/78>.

diff --git a/tests/generate.py b/tests/generate.py
index b639c8f..111ca41 100644
--- a/tests/generate.py
+++ b/tests/generate.py
@@ -63,3 +63,3 @@ class Module(object):
 
-        self.mtime = 0
+        self.mtime = None # Guix sets all file mtimes to '0'
         self.enabled = True
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<div class='path'>path: <a href='/guix/log/?id=135c9af111d3035dc8ea491afdcbb336016f61b5'>root</a>/<a href='/guix/log/etc?id=135c9af111d3035dc8ea491afdcbb336016f61b5'>etc</a>/<a href='/guix/log/etc/time-travel-manifest.scm?id=135c9af111d3035dc8ea491afdcbb336016f61b5'>time-travel-manifest.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/etc/time-travel-manifest.scm?id=135c9af111d3035dc8ea491afdcbb336016f61b5&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-08-17 15:42:56 +0200'>2022-08-17</span></td><td><a href='/guix/commit/etc/time-travel-manifest.scm?id=845c841e21379e64a4215ee6d3d60da343e7fb93'>time-travel-manifest: Use a separate cache per system.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/time-travel-manifest.scm (&lt;guix-instance-compiler&gt;): Use a separate
cache per system so that parallel system evaluations do no step on each
other's toes.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2022-07-10 23:57:14 +0200'>2022-07-10</span></td><td><a href='/guix/commit/etc/time-travel-manifest.scm?id=5d0437ea8ce0147b47b9df866fa2413b48f71a1a'>time-travel-manifest: Use a separate Git checkout cache.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/time-travel-manifest.scm (guix-instance-compiler): Parameterize
%REPOSITORY-CACHE-DIRECTORY.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-07-08 23:58:11 +0200'>2022-07-08</span></td><td><a href='/guix/commit/etc/time-travel-manifest.scm?id=e80f0cda96181d90604c44f69094f2499036b3f6'>etc: Add 'time-travel-manifest.scm'.</a><span class='msg-avail'>...<span class='msg-tooltip'>This manifest makes it easy to test travels from the current revision
back to the revision of a past Guix release.

Suggested by zimoun &lt;zimon.toutoune@gmail.com&gt;.

* etc/time-travel-manifest.scm: New file.
* Makefile.am (EXTRA_DIST): Add it.
</span></span></td><td>Ludovic Courtès</td></tr>