Python 3.11 test regressions due to changed exception messages

[mgorny]

(via tox -e py311, with Python 3.11.0b3)

============================================================== FAILURES ===============================================================
__________________________________________________ PropertyTestCase.test_literalname __________________________________________________

self = <cssutils.tests.test_property.PropertyTestCase testMethod=test_literalname>, excClass = <class 'AttributeError'>
msg = "can't set attribute", callableObj = <method-wrapper '__setattr__' of Property object at 0x7f9dfead21d0>
args = ('literalname', 'color'), kwargs = {}, excMsg = "property 'literalname' of 'Property' object has no setter"

    def assertRaisesMsg(self, excClass, msg, callableObj, *args, **kwargs):
        """
        Just like unittest.TestCase.assertRaises,
        but checks that the message is right too.
    
        Usage::
    
            self.assertRaisesMsg(
                MyException, "Exception message",
                my_function, (arg1, arg2)
                )
    
        from
        http://www.nedbatchelder.com/blog/200609.html#e20060905T064418
        """
        try:
>           callableObj(*args, **kwargs)
E           AttributeError: property 'literalname' of 'Property' object has no setter

/tmp/cssutils/cssutils/tests/basetest.py:105: AttributeError

During handling of the above exception, another exception occurred:

self = <cssutils.tests.test_property.PropertyTestCase testMethod=test_literalname>

    def test_literalname(self):
        "Property.literalname"
        p = cssutils.css.property.Property(r'c\olor', 'red')
        self.assertEqual(r'c\olor', p.literalname)
>       self.assertRaisesMsg(
            AttributeError, "can't set attribute", p.__setattr__, 'literalname', 'color'
        )

/tmp/cssutils/cssutils/tests/test_property.py:162: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <cssutils.tests.test_property.PropertyTestCase testMethod=test_literalname>, excClass = <class 'AttributeError'>
msg = "can't set attribute", callableObj = <method-wrapper '__setattr__' of Property object at 0x7f9dfead21d0>
args = ('literalname', 'color'), kwargs = {}, excMsg = "property 'literalname' of 'Property' object has no setter"

    def assertRaisesMsg(self, excClass, msg, callableObj, *args, **kwargs):
        """
        Just like unittest.TestCase.assertRaises,
        but checks that the message is right too.
    
        Usage::
    
            self.assertRaisesMsg(
                MyException, "Exception message",
                my_function, (arg1, arg2)
                )
    
        from
        http://www.nedbatchelder.com/blog/200609.html#e20060905T064418
        """
        try:
            callableObj(*args, **kwargs)
        except excClass as exc:
            excMsg = str(exc)
            if not msg:
                # No message provided: any message is fine.
                return
            elif msg in excMsg:
                # Message provided, and we got the right message: passes.
                return
            else:
                # Message provided, and it didn't match: fail!
>               raise self.failureException(
                    "Right exception, wrong message: got '%s' instead of '%s'"
                    % (excMsg, msg)
                )
E               AssertionError: Right exception, wrong message: got 'property 'literalname' of 'Property' object has no setter' instead of 'can't set attribute'

/tmp/cssutils/cssutils/tests/basetest.py:116: AssertionError
__________________________________________________ SelectorTestCase.test_specificity __________________________________________________

self = <cssutils.tests.test_selector.SelectorTestCase testMethod=test_specificity>, excClass = <class 'AttributeError'>
msg = "can't set attribute", callableObj = <function SelectorTestCase.test_specificity.<locals>._set at 0x7f9dfed3fce0>, args = ()
kwargs = {}, excMsg = "property 'specificity' of 'Selector' object has no setter"

    def assertRaisesMsg(self, excClass, msg, callableObj, *args, **kwargs):
        """
        Just like unittest.TestCase.assertRaises,
        but checks that the message is right too.
    
        Usage::
    
            self.assertRaisesMsg(
                MyException, "Exception message",
                my_function, (arg1, arg2)
                )
    
        from
        http://www.nedbatchelder.com/blog/200609.html#e20060905T064418
        """
        try:
>           callableObj(*args, **kwargs)

/tmp/cssutils/cssutils/tests/basetest.py:105: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

    def _set():
>       selector.specificity = 1
E       AttributeError: property 'specificity' of 'Selector' object has no setter

/tmp/cssutils/cssutils/tests/test_selector.py:386: AttributeError

During handling of the above exception, another exception occurred:

self = <cssutils.tests.test_selector.SelectorTestCase testMethod=test_specificity>

    def test_specificity(self):
        "Selector.specificity"
        selector = cssutils.css.Selector()
    
        # readonly
        def _set():
            selector.specificity = 1
    
>       self.assertRaisesMsg(AttributeError, "can't set attribute", _set)

/tmp/cssutils/cssutils/tests/test_selector.py:388: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <cssutils.tests.test_selector.SelectorTestCase testMethod=test_specificity>, excClass = <class 'AttributeError'>
msg = "can't set attribute", callableObj = <function SelectorTestCase.test_specificity.<locals>._set at 0x7f9dfed3fce0>, args = ()
kwargs = {}, excMsg = "property 'specificity' of 'Selector' object has no setter"

    def assertRaisesMsg(self, excClass, msg, callableObj, *args, **kwargs):
        """
        Just like unittest.TestCase.assertRaises,
        but checks that the message is right too.
    
        Usage::
    
            self.assertRaisesMsg(
                MyException, "Exception message",
                my_function, (arg1, arg2)
                )
    
        from
        http://www.nedbatchelder.com/blog/200609.html#e20060905T064418
        """
        try:
            callableObj(*args, **kwargs)
        except excClass as exc:
            excMsg = str(exc)
            if not msg:
                # No message provided: any message is fine.
                return
            elif msg in excMsg:
                # Message provided, and we got the right message: passes.
                return
            else:
                # Message provided, and it didn't match: fail!
>               raise self.failureException(
                    "Right exception, wrong message: got '%s' instead of '%s'"
                    % (excMsg, msg)
                )
E               AssertionError: Right exception, wrong message: got 'property 'specificity' of 'Selector' object has no setter' instead of 'can't set attribute'

/tmp/cssutils/cssutils/tests/basetest.py:116: AssertionError

[jaraco]

Thanks for the report. I do intend to add Python 3.11 support. I'm delayed due to actions/setup-python#213.

[jaraco]

With 141245e, tests now run against Python 3.11 in CI.

[jaraco]

Ugh. Once again, I'm finding the lxml dependency means the pipelines are broken in Python 3.11 until lxml provides binary builds for that Python version.

[mgorny]

At least on non-Windows targets, I guess you could also just install the needed packages and let lxml be built from source.

[mgorny]

For Linux, you could copy-paste it from https://github.com/pkgcore/pkgcheck/blob/master/.github/workflows/test.yml#L52

[jaraco]

Good tips. Yeah, I considered that, but I'm reluctant to tweak this project and half a dozen others only for a few months and only to get partial support (Windows would still need to be disabled). Good news is in #25, I found a mostly non-invasive solution that worked well enough to get us to the point that now the tests are running in CI and the two tests you identified are marked as xfail, so we can know when they're fixed.

[jaraco]

I notice that both errors are failing with the same mode. When I searched for the error message, I found this same issue was reported here in fedora.

[jaraco]

That bug implicates bpo-46730 / python/cpython#90886.

[jaraco]

In jaraco/jaraco.test@6ef8187, I've created a function that will provide the required expectation based on Python version. I'm unsure whether I want to employ that function or simply drop the check for the expected exception message.

[jaraco]

On further consideration, I think I do want to employ that function, to keep the status quo, but maybe remove it after.

[mgorny]

On further consideration, I think I do want to employ that function, to keep the status quo, but maybe remove it after.

Yeah, I think it'd be sufficient to do substring match for the property name.