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[macOS] test_builtin.PtyTests.test_input_tty hangs if rlcompleter is imported #116402
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Reduced amount of tests to trigger the hang:
./python.exe -m test test___all__ test_builtin Using random seed: 2282378935 0:00:00 load avg: 1.58 Run 2 tests sequentially 0:00:00 load avg: 1.58 [1/2] test___all__ 0:00:00 load avg: 1.58 [2/2] test_builtin ^C == Tests result: INTERRUPTED == 1 test omitted: test_builtin 1 test OK. Test suite interrupted by signal SIGINT. Total duration: 18.0 sec Total tests: run=1 Total test files: run=1/2 Result: INTERRUPTED
Minimal number of tests:
test.test___all__.AllTest.test_all test.test_builtin.PtyTests.test_input_ttyIt gets stuck here:
cpython/Lib/test/test_builtin.py
Line 2282 in d2f1b0e
Reacted by Kirill PodoprigoraSince
test_allactually imports all modules and executes them, the problem can be in any module :(I think that it would be easier to bisect when running only two test cases at least!
Reacted by Kirill PodoprigoraIf we skip import of
rlcompleterin thetest_all, then everything will be fine:diff --git a/Lib/test/test___all__.py b/Lib/test/test___all__.py index 19dcbb207e..c5bf4bb1ff 100644 --- a/Lib/test/test___all__.py +++ b/Lib/test/test___all__.py @@ -111,6 +111,8 @@ def test_all(self): lib_dir = os.path.dirname(os.path.dirname(__file__)) for path, modname in self.walk_modules(lib_dir, ""): m = modname + if m == "rlcompleter": + continue denied = False while m: if m in denylist:
./python.exe -m test test___all__ test_builtin Using random seed: 1172128194 0:00:00 load avg: 4.37 Run 2 tests sequentially 0:00:00 load avg: 4.37 [1/2] test___all__ 0:00:01 load avg: 4.37 [2/2] test_builtin == Tests result: SUCCESS == All 2 tests OK. Total duration: 1.7 sec Total tests: run=133 skipped=1 Total test files: run=2/2 Result: SUCCESS
Seems like problem in this import:
(sources ofLib/rlcompleter.py)try: import readline except ImportError: _readline_available = False else: readline.set_completer(Completer().complete) # Release references early at shutdown (the readline module's # contents are quasi-immortal, and the completer function holds a # reference to globals). atexit.register(lambda: readline.set_completer(None)) _readline_available = True
If a test fails with a completer callback is set, you can try to:
completer = readline.get_completer() try: readline.set_completer(None) ... # run the test finally: readline.set_completer(completer)But only do it if readline is in
sys.modules.- changed the title
[-]``test_builtin`` hangs when running the full test suite[/-][+]``test_builtin.PtyTests.test_input_tty`` hangs when run after test___all__[/+]on Mar 6, 2024 test.test_builtin.PtyTests.test_input_ttycan also be affected by other tests that importrlcompleter, and importingrlcompletercan also affect other tests. There may be several old issues which will be solved when solve this issue.I would add a code that restores (or just resets) the completer in
Lib/test/libregrtest/save_env.py.Reacted by Victor Stinner, Kirill Podoprigora and Łukasz Langareadline.set_completer(None)
If you fully want to control the TTY and not be affected by previous tests, another approach is to spawn a new process.
This might be a duplicate of #89050
This test hangs for me on a Mac even without running any other test:
% ./python.exe -m test test_builtin -m test_input_tty -v == CPython 3.14.0a0 (heads/pep649-inspect:ad8c51c157, May 31 2024, 08:27:05) [Clang 14.0.0 (clang-1400.0.29.202)] == macOS-13.4.1-arm64-arm-64bit-Mach-O little-endian == Python build: debug == cwd: /Users/jelle/py/cpython/build/test_python_worker_85845æ == CPU count: 8 == encodings: locale=UTF-8 FS=utf-8 == resources: all test resources are disabled, use -u option to unskip tests Using random seed: 1737450533 Raised RLIMIT_NOFILE: 256 -> 1024 0:00:00 load avg: 1.34 Run 1 test sequentially 0:00:00 load avg: 1.34 [1/1] test_builtin test_input_tty (test.test_builtin.PtyTests.test_input_tty) ... ^C == Tests result: INTERRUPTED ==- changed the title
[-]``test_builtin.PtyTests.test_input_tty`` hangs when run after test___all__[/-][+]``test_builtin.PtyTests.test_input_tty`` hangs if ``rlcompleter`` is imported[/+]on May 31, 2024 What I'm seeing is related to #112950, which made it so
pdbunconditionally importsrlcompleter;test_builtinimportsdoctestwhich importspdbwhich now importsrlcompleter. However, obviously there are many code paths that could causerlcompleterto be imported when this test runs.I tried locally to temporarily set the readline completer to None as @vstinner suggests above, but the test still hangs. I haven't looked more deeply to figure out what's going wrong.
Reacted by Łukasz LangaIf I comment out the import of
readlineinrlcompleter.py, the test intest_builtinno longer hangs. But getting rid of thereadline.set_completer()call inrlcompleter.pyis not sufficient to stop the test from hanging: justreadlinebeing present insys.modulesis sufficient to cause the hang.I see that many similar tests in
test_builtin.pyare simply skipped if"readline"is present insys.modules:cpython/Lib/test/test_builtin.py
Line 2400 in 64ff1e2
cpython/Lib/test/test_builtin.py
Line 2405 in 64ff1e2
cpython/Lib/test/test_builtin.py
Line 2415 in 64ff1e2
We could consider doing something similar here, though obviously it would be nice if the test could still be run even if
readlineis present insys.modules.- changed the title
[-]``test_builtin.PtyTests.test_input_tty`` hangs if ``rlcompleter`` is imported[/-][+][macOS] ``test_builtin.PtyTests.test_input_tty`` hangs if ``rlcompleter`` is imported[/+]on Jun 2, 2024 - added a commit that references this issue
on Jul 30, 2024 - added a commit that references this issue
on Jun 25, 2025
Bug report
Bug description:
CPython versions tested on:
CPython main branch
Operating systems tested on:
macOS
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