Python 3.7 tests are broken

[jonringer]

Describe the bug
Packaging this for nixpkgs, and noticed the python3.7 test suite is broken with the following error:

Error log

======================================================================
ERROR: test_glob (pyfakefs.tests.fake_pathlib_test.FakePathlibPathFileOperationTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/build/pyfakefs-3.7/pyfakefs/tests/fake_pathlib_test.py", line 710, in test_glob
    self.assertEqual(sorted(path.glob('*.py')),
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 1119, in glob
    selector = _make_selector(tuple(pattern_parts), self._flavour)
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 464, in _make_selector
    return cls(pat, child_parts, flavour)
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 520, in __init__
    self.match = flavour.compile_pattern(pat)
AttributeError: '_FakePosixFlavour' object has no attribute 'compile_pattern'

======================================================================
ERROR: test_glob_case_posix (pyfakefs.tests.fake_pathlib_test.FakePathlibPathFileOperationTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/build/pyfakefs-3.7/pyfakefs/tests/fake_pathlib_test.py", line 733, in test_glob_case_posix
    self.assertEqual(sorted(path.glob('*.py')),
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 1119, in glob
    selector = _make_selector(tuple(pattern_parts), self._flavour)
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 464, in _make_selector
    return cls(pat, child_parts, flavour)
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 520, in __init__
    self.match = flavour.compile_pattern(pat)
AttributeError: '_FakePosixFlavour' object has no attribute 'compile_pattern'

======================================================================
ERROR: test_glob_case_windows (pyfakefs.tests.fake_pathlib_test.FakePathlibPathFileOperationTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/build/pyfakefs-3.7/pyfakefs/tests/fake_pathlib_test.py", line 721, in test_glob_case_windows
    self.assertEqual(sorted(path.glob('*.py')),
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 1119, in glob
    selector = _make_selector(tuple(pattern_parts), self._flavour)
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 464, in _make_selector
    return cls(pat, child_parts, flavour)
  File "/nix/store/v543lrn8xkx5ylsa6g59l8s74jx3nh6p-python3-3.7.6/lib/python3.7/pathlib.py", line 520, in __init__
    self.match = flavour.compile_pattern(pat)
AttributeError: '_FakePosixFlavour' object has no attribute 'compile_pattern'

----------------------------------------------------------------------
Ran 1901 tests in 4.445s

FAILED (errors=3, skipped=745, expected failures=2)

It's also only failing on 3.7. 2.7,3.5,3.6,3.8 all seem to pass fine.

How To Reproduce

python3.7 -m pyfakefs.tests.all_tests

Your enviroment
Please run the following and paste the output.

$ nix run nixpkgs.nix-info -c nix-info -m
 - system: `"x86_64-linux"`
 - host os: `Linux 5.4.3, NixOS, 20.03pre205780.d942688fc13 (Markhor)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.3.1`
 - channels(jon): `"home-manager, nixos-20.03pre203904.bb1013511e1"`
 - channels(root): `"nixos-20.03pre205780.d942688fc13"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

pyfakefs 3.7

[mrbean-bremen]

Thanks! We didn't notice this due to an older Python 3.7 version used in the Travis tests.
I can confirm that this is reproducible both with Python 3.7.6 and Python 3.8.1, but didn't happen with the previous versions (3.7.5 and 3.8.0). Looks like the pathlib implementation has changed in these versions (which have been released after pyfakefs 3.7...).
I will try to understand that and get a fix together. I will probably make a dot release after this has been fixed.

[mrbean-bremen]

For reference - this has been introduced in pathlib in this commit.

[mrbean-bremen]

Fixed in master and 3.7.1 branch, added new 3.7.1 PyPi release.
Closing. Please reopen if you still have problems with 3.7.1.