Issue 37411: testEnviron (test.test_wsgiref.HandlerTests) fails when environment variable X is set

In Fedora CI, we use the environment variable X to set tests to skip:

https://src.fedoraproject.org/tests/python/blob/bd3ec9505cd37d80fe47fbb8234928abcfc0c658/f/selftest/parallel.sh#_9 - lines 9 and 21

However, I'Ve realized that testEnviron (test.test_wsgiref.HandlerTests) fails.

Here's a reproducer:

$ python3.7 -m test test_wsgiref 
Run tests sequentially
0:00:00 load avg: 0.75 [1/1] test_wsgiref

== Tests result: SUCCESS ==

1 test OK.

Total duration: 77 ms
Tests result: SUCCESS


$ X=boom python3.7 -m test test_wsgiref 
Run tests sequentially
0:00:00 load avg: 0.71 [1/1] test_wsgiref
test test_wsgiref failed -- Traceback (most recent call last):
  File "/usr/lib64/python3.7/test/test_wsgiref.py", line 567, in testEnviron
    self.checkOSEnviron(h)
  File "/usr/lib64/python3.7/test/test_wsgiref.py", line 559, in checkOSEnviron
    self.assertEqual(env[k],v)
AssertionError: 'Y' != 'boom'
- Y
+ boom


test_wsgiref failed

== Tests result: FAILURE ==

1 test failed:
    test_wsgiref

Total duration: 73 ms
Tests result: FAILURE


I believe that such tests should not be so easily fooled - it should be properly isolated or a less common variable name should be used if that is not possible, such as PYTHON_TEST_WSGIREF_TMP instead of X.

I wrote PR 14394 to fix the test.

New changeset 5150d327924959639215ed0a78feffc0d88258da by Victor Stinner in branch 'master':
bpo-37411: Rewrite test_wsgiref.testEnviron() (GH-14394)
https://github.com/python/cpython/commit/5150d327924959639215ed0a78feffc0d88258da

New changeset 814c7aefc2b8e9892bce3d59c0ab39563d658aa2 by Miss Islington (bot) in branch '3.7':
bpo-37411: Rewrite test_wsgiref.testEnviron() (GH-14394)
https://github.com/python/cpython/commit/814c7aefc2b8e9892bce3d59c0ab39563d658aa2

New changeset bdbd5e895ddf9aefcb79cdc52341f0697ad6aea0 by Miss Islington (bot) in branch '3.8':
bpo-37411: Rewrite test_wsgiref.testEnviron() (GH-14394)
https://github.com/python/cpython/commit/bdbd5e895ddf9aefcb79cdc52341f0697ad6aea0

New changeset dfa9499ccbc14a4227ca8d0c1728e2beacbb45c6 by Victor Stinner (Miss Islington (bot)) in branch '2.7':
[2.7] bpo-37411: Rewrite test_wsgiref.testEnviron() (GH-14394) (GH-14404)
https://github.com/python/cpython/commit/dfa9499ccbc14a4227ca8d0c1728e2beacbb45c6

Ok, the bug is now fixed in 2.7, 3.7, 3.8 and master branches. Thanks Miro for the report. I also enhanced the test to test all variables of handler.environ.

stage: patch review -> resolved