pytest 7.0.0rc1 and 6.2.5 both fail test_errors_in_xfail_skip_expressions on Python 3.10.1

[hroncok]

In Fedora, when we updated Python from 3.10.0 to 3.10.1, the following test started to fail when we build pytest 6.2.5:

____________________ test_errors_in_xfail_skip_expressions _____________________
pytester = <Pytester PosixPath('/tmp/pytest-of-mockbuild/pytest-0/test_errors_in_xfail_skip_expressions0')>
    def test_errors_in_xfail_skip_expressions(pytester: Pytester) -> None:
        pytester.makepyfile(
            """
            import pytest
            @pytest.mark.skipif("asd")
            def test_nameerror():
                pass
            @pytest.mark.xfail("syntax error")
            def test_syntax():
                pass
    
            def test_func():
                pass
        """
        )
        result = pytester.runpytest()
        markline = "                ^"
        pypy_version_info = getattr(sys, "pypy_version_info", None)
        if pypy_version_info is not None and pypy_version_info < (6,):
            markline = markline[5:]
        elif sys.version_info[:2] >= (3, 10):
            markline = markline[11:]
        elif sys.version_info >= (3, 8) or hasattr(sys, "pypy_version_info"):
            markline = markline[4:]
    
        if sys.version_info[:2] >= (3, 10):
            expected = [
                "*ERROR*test_nameerror*",
                "*asd*",
                "",
                "During handling of the above exception, another exception occurred:",
            ]
        else:
            expected = [
                "*ERROR*test_nameerror*",
            ]
    
        expected += [
            "*evaluating*skipif*condition*",
            "*asd*",
            "*ERROR*test_syntax*",
            "*evaluating*xfail*condition*",
            "    syntax error",
            markline,
            "SyntaxError: invalid syntax",
            "*1 pass*2 errors*",
        ]
>       result.stdout.fnmatch_lines(expected)
E       Failed: nomatch: '*ERROR*test_nameerror*'
E           and: '============================= test session starts =============================='
E           and: 'platform linux -- Python 3.10.1, pytest-6.2.5, py-1.11.0, pluggy-1.0.0'
E           and: 'rootdir: /tmp/pytest-of-mockbuild/pytest-0/test_errors_in_xfail_skip_expressions0'
E           and: 'collected 3 items'
E           and: ''
E           and: 'test_errors_in_xfail_skip_expressions.py EE.                             [100%]'
E           and: ''
E           and: '==================================== ERRORS ===================================='
E       fnmatch: '*ERROR*test_nameerror*'
E          with: '_______________________ ERROR at setup of test_nameerror _______________________'
E       fnmatch: '*asd*'
E          with: "name 'asd' is not defined"
E       exact match: ''
E       exact match: 'During handling of the above exception, another exception occurred:'
E       fnmatch: '*evaluating*skipif*condition*'
E          with: "Error evaluating 'skipif' condition"
E       fnmatch: '*asd*'
E          with: '    asd'
E       nomatch: '*ERROR*test_syntax*'
E           and: "NameError: name 'asd' is not defined"
E       fnmatch: '*ERROR*test_syntax*'
E          with: '________________________ ERROR at setup of test_syntax _________________________'
E       nomatch: '*evaluating*xfail*condition*'
E           and: 'invalid syntax (<xfail condition>, line 1)'
E           and: ''
E           and: 'During handling of the above exception, another exception occurred:'
E       fnmatch: '*evaluating*xfail*condition*'
E          with: "Error evaluating 'xfail' condition"
E       exact match: '    syntax error'
E       nomatch: '     ^'
E           and: '            ^'
E           and: 'SyntaxError: invalid syntax'
E           and: '=========================== short test summary info ============================'
E           and: 'ERROR test_errors_in_xfail_skip_expressions.py::test_nameerror'
E           and: 'ERROR test_errors_in_xfail_skip_expressions.py::test_syntax'
E           and: '========================= 1 passed, 2 errors in 0.01s =========================='
E       remains unmatched: '     ^'
/builddir/build/BUILD/pytest-6.2.5/testing/test_skipping.py:1156: Failed
----------------------------- Captured stdout call -----------------------------
============================= test session starts ==============================
platform linux -- Python 3.10.1, pytest-6.2.5, py-1.11.0, pluggy-1.0.0
rootdir: /tmp/pytest-of-mockbuild/pytest-0/test_errors_in_xfail_skip_expressions0
collected 3 items
test_errors_in_xfail_skip_expressions.py EE.                             [100%]
==================================== ERRORS ====================================
_______________________ ERROR at setup of test_nameerror _______________________
name 'asd' is not defined
During handling of the above exception, another exception occurred:
Error evaluating 'skipif' condition
    asd
NameError: name 'asd' is not defined
________________________ ERROR at setup of test_syntax _________________________
invalid syntax (<xfail condition>, line 1)
During handling of the above exception, another exception occurred:
Error evaluating 'xfail' condition
    syntax error
            ^
SyntaxError: invalid syntax
=========================== short test summary info ============================
ERROR test_errors_in_xfail_skip_expressions.py::test_nameerror
ERROR test_errors_in_xfail_skip_expressions.py::test_syntax
========================= 1 passed, 2 errors in 0.01s ==========================
...
====== 1 failed, 3035 passed, 11 skipped, 10 xfailed in 278.15s (0:04:38) ======

I get the same failure when I attempt to update to 7.0.0rc1.

I suppose this is related to

pytest/testing/test_skipping.py

Lines 1146 to 1147 in a335ade

	elif sys.version_info[:2] >= (3, 10):
	markline = markline[11:]

[bluetech]

This is failing our CI as well now: https://github.com/pytest-dev/pytest/runs/4546996445?check_suite_focus=true