$ ./python -m test.regrtest test_inspect test_site
    Run tests sequentially
    0:00:00 load avg: 0.03 [1/2] test_inspect
    0:00:00 load avg: 0.03 [2/2] test_site
    test test_site failed -- Traceback (most recent call last):
      File "/home/yen/Projects/cpython/Lib/test/test_site.py", line 400, in test_abs_paths_cached_None
        site.abs_paths()
      File "/home/yen/Projects/cpython/Lib/site.py", line 101, in abs_paths
        for m in set(sys.modules.values()):
    TypeError: unhashable type: 'dict'

test_site failed

If I run test_inspect or test_site individually, both pass. Full log can be found in the attached file.

Environment: Arch Linux x86_64 latest. CPython commit 81574b8, configured with ./configure

You can try to limit the number of tests needed to reproduce the bug using:

./python -m test.bisect -n 5 test_inspect test_site

The failing test was added with d4c76d9

commit d4c76d9
Author: INADA Naoki <methane@users.noreply.github.com>
Date: Mon Oct 1 21:10:37 2018 +0900

bpo-30167: Add test for module.__cached__ is None (GH-7617)

diff --git a/Lib/test/test_site.py b/Lib/test/test_site.py
index dc59e5917c..33a8f1a44c 100644
--- a/Lib/test/test_site.py
+++ b/Lib/test/test_site.py
@@ -389,6 +389,17 @@ class ImportSideEffectTests(unittest.TestCase):
"expected absolute path, got {}"
.format(os__cached__.decode('ascii')))

+ def test_abs_paths_cached_None(self):
+ """Test for __cached__ is None.
+
+ Regarding to PEP-3147, __cached__ can be None.
+
+ See also: https://bugs.python.org/issue30167
+ """
+ sys.modules['test'].__cached__ = None
+ site.abs_paths()
+ self.assertIsNone(sys.modules['test'].__cached__)
+

# Latest master

➜  cpython git:(master) ./python.exe -m test.regrtest test_inspect test_site
Run tests sequentially
0:00:00 load avg: 1.75 [1/2] test_inspect
0:00:02 load avg: 1.75 [2/2] test_site
test test_site failed -- Traceback (most recent call last):
  File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/test/test_site.py", line 400, in test_abs_paths_cached_None
    site.abs_paths()
  File "/Users/karthikeyansingaravelan/stuff/python/cpython/Lib/site.py", line 101, in abs_paths
    for m in set(sys.modules.values()):
TypeError: unhashable type: 'dict'

test_site failed

== Tests result: FAILURE ==

1 test OK.

1 test failed:
test_site

Total duration: 2 sec 868 ms
Tests result: FAILURE

➜ cpython git:(master) git checkout d4c76d9~1 Lib/test/test_site.py
➜ cpython git:(master) ✗ ./python.exe -m test.regrtest test_inspect test_site
Run tests sequentially
0:00:00 load avg: 1.49 [1/2] test_inspect
0:00:02 load avg: 1.49 [2/2] test_site

== Tests result: SUCCESS ==

All 2 tests OK.

Total duration: 2 sec 848 ms
Tests result: SUCCESS

Adding INADA Naoki for thoughts.

Thanks

Thanks very much for the test.bisect hint! After some more trials, I guess it's an issue in the inspect module rather than the newly-added test in test_site. Here's an example script:

import inspect
import sys
import _testcapi

builtin = _testcapi.docstring_with_signature_with_defaults
spec = inspect.getfullargspec(builtin)
print(type(sys.modules['__builtins__']))

After inspect.getfullargspec(), sys.modules['__builtins__'] is a dict. That's a little bit strange as every other item in sys.modules is a module.

New changeset c57eb9a by Miss Islington (bot) (Chih-Hsuan Yen) in branch 'master':
bpo-34871: Fix two typos in test_inspect.py (GH-9698)
c57eb9a

New changeset 6f85b82 by Miss Islington (bot) (INADA Naoki) in branch 'master':
bpo-34871: inspect: Don't pollute sys.modules (GH-9696)
6f85b82

New changeset 70a083b by Yury Selivanov (Miss Islington (bot)) in branch '3.6':
bpo-34871: inspect: Don't pollute sys.modules (GH-9696) (GH-9702)
70a083b

New changeset 476c294 by Yury Selivanov (Miss Islington (bot)) in branch '3.7':
bpo-34871: inspect: Don't pollute sys.modules (GH-9696) (bpo-9701)
476c294

Thank you Inada-san for taking care of this.