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

diff --git a/giscanner/__init__.py b/giscanner/__init__.py
index 7c2f365a..607fe341 100644
--- a/giscanner/__init__.py
+++ b/giscanner/__init__.py
@@ -21,6 +21,8 @@ import os
 builddir = os.environ.get('UNINSTALLED_INTROSPECTION_BUILDDIR')
 if builddir is not None:
     __path__.append(os.path.join(builddir, 'giscanner'))  # type: ignore  # mypy issue #1422
+if not 'CC' in os.environ:
+    os.environ['CC'] = 'gcc'
 try:
     from ._version import __version__
 except ImportError:
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<tr class='logheader'><td><span title='2024-04-28 10:01:29 -0400'>2024-04-28</span></td><td class='logsubject'><a href='/guix/commit/gnu/packages/certs.scm?id=baa6d7e04e2b36fe35ddf4f69d842ae253129fae'>gnu: nss-certs: Update to 3.99.</a></td><td>Ian Eure</td></tr>
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* gnu/packages/certs.scm (nss-certs): Update to 3.99.

Change-Id: I588bc385022df486e596cd6fc5a7363df919b80b
Signed-off-by: Maxim Cournoyer &lt;maxim.cournoyer@gmail.com&gt;


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<tr class='logheader'><td><span title='2024-04-12 14:21:39 +0300'>2024-04-12</span></td><td class='logsubject'><a href='/guix/commit/gnu/packages/certs.scm?id=0920693381d9f6b7923e69fe00be5de8621ddb6f'>gnu: Add nss-certs-3.98.</a></td><td>Ian Eure</td></tr>
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* gnu/packages/certs.scm (nss-certs-3.98): New variable.

Change-Id: I95b54781c7b85f1d6b54158c6b906116791e009c
Signed-off-by: Andrew Tropin &lt;andrew@trop.in&gt;


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