Tests fail when `_interpreters` extension is disabled

[TrueCat17]

Bug report

Bug description:

My CPython version: 3.14.4 (problem with 3.14.3 too)

Configure:
./configure --disable-shared --enable-optimizations --without-lto

Select modules:

./Modules/makesetup -c ./Modules/config.c.in -s ./Modules ./Setup.my.local
mv config.c ./Modules/

File (github says *.local file upload is not expected, change ext txt -> local)
Setup.my.txt
As you can see, the _interpreters module is disabled

And make:
make -j4

Error after testing:

...
File ".../Lib/test/datetimetester.py", line 7304, in test_concurrent_initialization_subinterpreter
...
Traceback (most recent call last):
  File "<string>", line 2, in <module>
    from concurrent.futures import InterpreterPoolExecutor
ImportError: cannot import name 'InterpreterPoolExecutor' from 'concurrent.futures'
...
Ran 1098 tests in 10.101s

FAILED (failures=1, skipped=53)
test test_datetime failed
make: *** [Makefile:990: profile-run-stamp] Error 2

I think a test with a non-existent module should be skipped, not crashed
Also, why does a test failure cause the build to fail if these tests are just needed to collect statistics?

CPython versions tested on:

3.14

Operating systems tested on:

Linux

[StanFromIreland]

Also, why does a test failure cause the build to fail if these tests are just needed to collect statistics?

The build succeed, just the test failed.

[TrueCat17]

No, building stops after tests failed (in my case)

[Shrey-N]

Hiya, I believe that the failure is caused by InterpreterPoolExecutor being missing from concurrent.futures when the _interpreters module is disabled, The test should be skipped in this case

Adding @unittest.skipIf(_interpreters is None, "requires _interpreters") "requires _interpreters") to the test resolves this issue

I am just making a PR fixing this issue within a minute!

Thank you for the bug report :)

[StanFromIreland]

@sunmy2019 out of curiosity, what does this have to do with building?

[Shrey-N]

out of curiosity, what does this have to do with building?

I think the build stops because the Makefile is configured to quit immediately if any test crashes.

[vstinner]

Currently, we don't support custom Python builds disabling the _interpreters extension. If you do that, you have to patch the test suite to skip tests using it.

[StanFromIreland]

I think the build stops because the Makefile is configured to quit immediately if any test crashes.

But that's the same for any test...? It has nothing to with building in particular.

[StanFromIreland]

Disabling _interpreters will lead to many other fails, on my system I get:

14 tests failed:
    test.test_concurrent_futures.test_as_completed
    test.test_concurrent_futures.test_deadlock
    test.test_concurrent_futures.test_future
    test.test_concurrent_futures.test_init
    test.test_concurrent_futures.test_interpreter_pool
    test.test_concurrent_futures.test_process_pool
    test.test_concurrent_futures.test_shutdown
    test.test_concurrent_futures.test_thread_pool
    test.test_concurrent_futures.test_wait test__interpchannels
    test_datetime test_interpreters

[Shrey-N]

Oh, yea you are right, _interpreters being disabled breaks many tests I will update the fix, i think we can add skips to the test_interpreters package and the executor tests in test_concurrent_futures

[Shrey-N]

Currently, we don't support custom Python builds disabling the _interpreters extension. If you do that, you have to patch the test suite to skip tests using it.

Got it @vstinner, Just to clarify does that mean a patch adding these test skips wouldn't be accepted? I think it would be a nice thing to add