my guix describe: Generation 3 May 12 2020 09:03:13 (current) guix 91be384 repository URL: /opt/guix branch: master commit: 91be384d2ef87af58f814e10a4ce0d8717bea647 (I store the git repository in /opt/guix and pull the source code of upstream https://github.com/guix-mirror/guix) build log: =================================== FAILURES =================================== _______________ test_python_exception_matches[(lambda: x := 1)] ________________ code = '(lambda: x := 1)' @pytest.mark.parametrize('code', FAILING_EXAMPLES) def test_python_exception_matches(code): wanted, line_nr = _get_actual_exception(code) errors = _get_error_list(code) wanted, line_nr = _get_actual_exception(code) [50/1848] errors = _get_error_list(code) actual = None if errors: error, = errors actual = error.message > assert actual in wanted E AssertionError: assert 'SyntaxError: cannot use named assignment with subscript' in ['SyntaxError: cannot use assignment expressions with subscript'] test/test_python_errors.py:39: AssertionError __________________ test_python_exception_matches[(a(i) := x)] __________________ code = '(a(i) := x)' @pytest.mark.parametrize('code', FAILING_EXAMPLES) def test_python_exception_matches(code): wanted, line_nr = _get_actual_exception(code) errors = _get_error_list(code) actual = None if errors: error, = errors actual = error.message > assert actual in wanted E AssertionError: assert 'SyntaxError: cannot use named assignment with function call' in ['SyntaxError: cannot use assignment expressions with function call'] test/test_python_errors.py:39: AssertionError __________________ test_python_exception_matches[(a.b := c)] ___________________ code = '(a.b := c)' @pytest.mark.parametrize('code', FAILING_EXAMPLES) def test_python_exception_matches(code): wanted, line_nr = _get_actual_exception(code) errors = _get_error_list(code) actual = None if errors: error, = errors actual = error.message > assert actual in wanted E AssertionError: assert 'SyntaxError: cannot use named assignment with attribute' in ['SyntaxError: cannot use assignment expressions with attribute'] test/test_python_errors.py:39: AssertionError _____ test_python_exception_matches[[(i.i:= 0) for ((i), j) in range(5)]] ______ code = '[(i.i:= 0) for ((i), j) in range(5)]' @pytest.mark.parametrize('code', FAILING_EXAMPLES) def test_python_exception_matches(code): wanted, line_nr = _get_actual_exception(code) def test_python_exception_matches(code): [0/1848] wanted, line_nr = _get_actual_exception(code) errors = _get_error_list(code) actual = None if errors: error, = errors actual = error.message > assert actual in wanted E AssertionError: assert 'SyntaxError: cannot use named assignment with attribute' in ['SyntaxError: cannot use assignment expressions with attribute'] test/test_python_errors.py:39: AssertionError ________________ test_python_exception_matches[(await a := x)] _________________ code = '(await a := x)' @pytest.mark.parametrize('code', FAILING_EXAMPLES) def test_python_exception_matches(code): wanted, line_nr = _get_actual_exception(code) errors = _get_error_list(code) actual = None if errors: error, = errors actual = error.message > assert actual in wanted E AssertionError: assert 'SyntaxError: cannot use named assignment with await expression' in ['SyntaxError: cannot use assignment expressions with await expression '] test/test_python_errors.py:39: AssertionError _______________ test_python_exception_matches[((await a) := x)] ________________ code = '((await a) := x)' @pytest.mark.parametrize('code', FAILING_EXAMPLES) def test_python_exception_matches(code): wanted, line_nr = _get_actual_exception(code) errors = _get_error_list(code) actual = None if errors: error, = errors actual = error.message > assert actual in wanted E AssertionError: assert 'SyntaxError: cannot use named assignment with await expression' in ['SyntaxError: cannot use assignment expressions with await expression '] test/test_python_errors.py:39: AssertionError ================== 9 failed, 1181 passed, 1 xfailed in 17.76s ================== command "pytest" "-vv" failed with status 1 How should I solve it?