Fix typing alias

[cdce8p]

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Description

Replaces #913
CC: @hippo91 @Pierre-Sassoulas

Type of Changes

	Type
✓	🐛 Bug fix

Related Issue

Closes #905
Closes pylint-dev/pylint#4093
Closes pylint-dev/pylint#4131
Closes pylint-dev/pylint#4145
Closes pylint-dev/pylint#3247
Closes pylint-dev/pylint#2717

[cdce8p]

@Pierre-Sassoulas It would be great if you could look at over one last time. Just to make sure I didn't miss something obvious. I'm running some tests at the moment to check if everything is good.

[Pierre-Sassoulas]

This could benefit from a rewrite using pre-commit for each commit: git rebase upstream/master -i --exec="pre-commit run --all-fles". Also it's the last thing we need to merge for 2.5.1, right ?

[Pierre-Sassoulas]

Or maybe we just squash.

[cdce8p]

Or maybe we just squash.

I would do a squash merge

Also it's the last thing we need to merge for 2.5.1, right ?

The version needs to be updated, but otherwise I believe that's it.

--

I noticed a moment ago the the Python 3.7 test is failing. I'll have to check that first.

[cdce8p]

Strange, Appveyor was fine and Travis had an error for 3.7.
Anyway I pushed a small change which should trigger the CI tests, although it doesn't change much.

[cdce8p]

Unfortunately some more errors, this time with pylint: https://github.com/cdce8p/pylint/runs/1999076587?check_suite_focus=true#step:6:205
This seems to be more serious, so I would like to address it before merging.

[Pierre-Sassoulas]

👍

[cdce8p]

I really hope all the tests pass now. Was a bit more difficult to fix than I expected.

[cdce8p]

@Pierre-Sassoulas Can you reproduce the Travis issue. I unfortunately can't 😞
https://travis-ci.org/github/PyCQA/astroid/jobs/760830892

[Pierre-Sassoulas]

Hmm it's strange, on 2391061 I have an error but not the same than for Travis

____ ExceptionModelTest.test_oserror __

self = <tests.unittest_object_model.ExceptionModelTest testMethod=test_oserror>

    def test_oserror(self):
        ast_nodes = builder.extract_node(
            """
        try:
            raise OSError("a")
        except OSError as err:
           err.filename #@
           err.filename2 #@
           err.errno #@
        """
        )
        expected_values = ["", "", 0]
        for node, value in zip(ast_nodes, expected_values):
            inferred = next(node.infer())
>           assert isinstance(inferred, astroid.Const)
E           AssertionError: assert False
E            +  where False = isinstance(Uninferable, <class 'astroid.node_classes.Const'>)
E            +    where <class 'astroid.node_classes.Const'> = astroid.Const

[cdce8p]

Hmm. Should I just change the required version to 3.8?
Since it works with AppVeyor Link, I would assume that this is a Travis issue.

[cdce8p]

@Pierre-Sassoulas I think it's done. Nothing unexpected with any tests.
I'll prepare pylint-dev/pylint#4152 for the astroid update in pylint.

[Pierre-Sassoulas]

Sounds good, I'll release astroid 2.5.1 asap :)