Use gcc as the default C compiler if CC is not set.

diff -ru gobject-introspection-1.58.1.orig/giscanner/__init__.py gobject-introspection-1.58.1/giscanner/__init__.py
--- gobject-introspection-1.58.1.orig/giscanner/__init__.py	1970-01-01 01:00:00.000000000 +0100
+++ gobject-introspection-1.58.1/giscanner/__init__.py	2018-12-03 13:33:28.788971299 +0100
@@ -22,6 +22,8 @@
 builddir = os.environ.get('UNINSTALLED_INTROSPECTION_BUILDDIR')
 if builddir is not None:
     __path__.append(os.path.join(builddir, 'giscanner'))
+if not 'CC' in os.environ:
+    os.environ['CC'] = 'gcc'
 try:
     from ._version import __version__
 except ImportError:
='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
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<div class='path'>path: <a href='/guix/log/?id=6a805f22a3b4ecff668c21b7ef5017321c27036c'>root</a>/<a href='/guix/log/po?id=6a805f22a3b4ecff668c21b7ef5017321c27036c'>po</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/po?id=6a805f22a3b4ecff668c21b7ef5017321c27036c&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-09-02 04:06:52 +0200'>2021-09-02</span></td><td><a href='/guix/commit/po?id=1ff2092a39dc5c7c7cd9b4a0ba4b59f92e738efc'>nls: Update translations.</a><span class='msg-avail'>...<span class='msg-tooltip'>* po/packages/it.po: New file.
* po/packages/LINGUAS: Add `it'.
* po/*/*.po: Update translations.
</span></span></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2021-08-21 19:25:46 +0200'>2021-08-21</span></td><td><a href='/guix/commit/po?id=a1dbc8be95369f4ff805117b8966dfd1364c396f'>po: Correct minetest importer in POTFILES.in.</a><span class='msg-avail'>...<span class='msg-tooltip'>The previous value references a file that does not exist, thus breaking
`make install'.

* po/guix/POTFILES.in: Swap out `guix/scripts/import/contentdb.scm' for
`guix/scripts/import/minetest.scm'.
</span></span></td><td>Leo Prikler</td></tr>
<tr><td><span title='2021-08-20 12:41:54 +0200'>2021-08-20</span></td><td><a href='/guix/commit/po?id=467e874a86dc3dd83fe10e5610823c011de6565a'>guix: Add ContentDB importer.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/import/contentdb.scm: New file.
* guix/scripts/import/contentdb.scm: New file.
* tests/contentdb.scm: New file.
* Makefile.am (MODULES, SCM_TESTS): Register them.
* po/guix/POTFILES.in: Likewise.
* doc/guix.texi (Invoking guix import): Document it.

Signed-off-by: Leo Prikler &lt;leo.prikler@student.tugraz.at&gt;
</span></span></td><td>Maxime Devos</td></tr>
scovery
should be enabled.  Set the '--discover' argument accordingly.
(prompt_yes_no): Add a trailing space to the message.
(sys_authorize_build_farms): Remove trailing space from the message argument.
* NEWS (Distribution): Add news.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-06-29 14:53:21 -0400'>2021-06-29</span></td><td><a href='/guix/commit/NEWS?id=82daab42811a2e3c7684ebdf12af75ff0fa67b99'>pack: Add support for the deb format.</a><span class='msg-avail'>...<span class='msg-tooltip'>* .dir-locals.el (scheme-mode)[gexp-&gt;derivation]: Define indentation rule.
* guix/scripts/pack.scm (debian-archive): New procedure.
(%formats): Register the new deb format.
(show-formats): Add it to the usage string.
* tests/pack.scm (%ar-bootstrap): New variable.
(deb archive with symlinks): New test.
* doc/guix.texi (Invoking guix pack): Document it.
* NEWS: Add news entry.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-05-10 13:48:30 -0400'>2021-05-10</span></td><td><a href='/guix/commit/NEWS?id=80dc6ad4a89b68b5e837fc22c9b1322b86527bef'>Update NEWS.</a></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-05-10 11:21:02 -0400'>2021-05-10</span></td><td><a href='/guix/commit/NEWS?id=7418a200742768d21b567916b25e4d3351472230'>Update NEWS.</a></td><td>Leo Famulari</td></tr>
<tr><td><span title='2021-05-10 11:42:03 +0200'>2021-05-10</span></td><td><a href='/guix/commit/NEWS?id=3a0fcaa0fe721792d1543e863c3fba805376bdac'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-05-04 16:57:05 +0200'>2021-05-04</span></td><td><a href='/guix/commit/NEWS?id=b37ab28401c55adbb8e36ea2931849636752524d'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-11-22 20:27:28 +0100'>2020-11-22</span></td><td><a href='/guix/commit/NEWS?id=a099685659b4bfa6b3218f84953cbb7ff9e88063'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-11-13 09:13:56 +0100'>2020-11-13</span></td><td><a href='/guix/commit/NEWS?id=1e272d42f6217b70c9801b93e46b144e9ab27664'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-11-09 23:27:09 +0100'>2020-11-09</span></td><td><a href='/guix/commit/NEWS?id=b51da3ccef74e5842b87e39eea839e36831e844e'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-11-07 19:36:10 +0100'>2020-11-07</span></td><td><a href='/guix/commit/NEWS?id=afa77bd2287f303aefdd00193309ccf57f6dcd93'>Update NEWS.</a></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2020-11-07 16:14:03 +0100'>2020-11-07</span></td><td><a href='/guix/commit/NEWS?id=e8b9b0fae076a86e2be1dcb87b666d4490bac0aa'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-11-05 23:27:22 +0100'>2020-11-05</span></td><td><a href='/guix/commit/NEWS?id=51916455d0bb283489162ef84afc8145b28b012c'>Update NEWS.</a></td><td>Ludovic Courtès</td></tr>