Use gcc as the default C compiler if CC is not set. --- gobject-introspection-1.44.0.orig/giscanner/__init__.py 2014-08-04 22:37:07.000000000 +0800 +++ gobject-introspection-1.44.0/giscanner/__init__.py 2015-04-20 17:30:26.507697234 +0800 @@ -22,3 +22,5 @@ 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'