def test_configure_new_option(self) -> None:
        """Adding a new option without reconfiguring should work."""
        testdir = self.copy_srcdir(os.path.join(self.common_test_dir, '40 options'))
        self.init(testdir)
        with open(os.path.join(testdir, 'meson_options.txt'), 'a', encoding='utf-8') as f:
            f.write("option('new_option', type : 'boolean', value : false)")
        self.setconf('-Dnew_option=true')
        self.assertEqual(self.getconf('new_option'), True)
Adding a new option without reconfiguring should work.
unittests/platformagnostictests.py