def test_ignore_libs(self):
        '''
        Test that find_library on libs that are to be ignored returns an empty
        array of arguments. Must be a unit test because we cannot inspect
        ExternalLibraryHolder from build files.
        '''
        testdir = os.path.join(self.platform_test_dir, '1 basic')
        env = get_fake_env(testdir, self.builddir, self.prefix)
        cc = detect_c_compiler(env, MachineChoice.HOST)
        if cc.get_argument_syntax() != 'msvc':
            raise SkipTest('Not using MSVC')
        # To force people to update this test, and also test
        self.assertEqual(set(cc.ignore_libs), {'c', 'm', 'pthread', 'dl', 'rt', 'execinfo'})
        for l in cc.ignore_libs:
            self.assertEqual(cc.find_library(l, env, []), [])

        Test that find_library on libs that are to be ignored returns an empty
        array of arguments. Must be a unit test because we cannot inspect
        ExternalLibraryHolder from build files.
        
unittests/windowstests.py