python / python/cpython

test_ctypes.test_find seems to pass when it shouldn't

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tests topic-ctypes type-bug
Dominant language
Python
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Description

Bug report

Bug description:

I have a container that has no compiler but does have ld:

$ gcc --version
-sh: gcc: command not found
$ ld --version
GNU ld (GNU Binutils) 2.46

If I run the test_ctypes tests, specifically test_find_library_with_gcc which looks like it will need gcc, it surprisingly passes:

$ python3 -mtest -v test_ctypes.test_find
== CPython 3.14.5 (main, May 10 2026, 10:21:34) [GCC 16.1.0]
== Linux-6.18.33-yocto-standard-aarch64-with-glibc2.43 little-endian
== Python build: release shared
== cwd: /tmp/test_python_worker_332æ
== CPU count: 4
== encodings: locale=ANSI_X3.4-1968 FS=utf-8
== resources: all test resources are disabled, use -u option to unskip tests

test_find (test.test_ctypes.test_find.FindLibraryAndroid.test_find) ... skipped 'Test only valid for Android'
test_find_nothing_with_wrong_ld_library_path (test.test_ctypes.test_find.FindLibraryEmscripten.test_find_nothing_with_wrong_ld_library_path) ... skipped 'Test only valid for Emscripten'
test_find_nothing_without_ld_library_path (test.test_ctypes.test_find.FindLibraryEmscripten.test_find_nothing_without_ld_library_path) ... skipped 'Test only valid for Emscripten'
test_find_wasm_file_with_so_extension (test.test_ctypes.test_find.FindLibraryEmscripten.test_find_wasm_file_with_so_extension) ... skipped 'Test only valid for Emscripten'
test_find_wasm_file_with_wasm_extension (test.test_ctypes.test_find.FindLibraryEmscripten.test_find_wasm_file_with_wasm_extension) ... skipped 'Test only valid for Emscripten'
test_ignore_non_wasm_file (test.test_ctypes.test_find.FindLibraryEmscripten.test_ignore_non_wasm_file) ... skipped 'Test only valid for Emscripten'
test_find_library_with_gcc (test.test_ctypes.test_find.FindLibraryLinux.test_find_library_with_gcc) ... ok
test_find_library_with_ld (test.test_ctypes.test_find.FindLibraryLinux.test_find_library_with_ld) ... ok
test_find_on_libpath (test.test_ctypes.test_find.FindLibraryLinux.test_find_on_libpath) ... skipped 'gcc, needed for test, not available'
test_gh114257 (test.test_ctypes.test_find.FindLibraryLinux.test_gh114257) ... ok
OpenGL libraries:
	 ('GL', None)
	 ('GLU', None)
	 ('gle', None)
test_gl (test.test_ctypes.test_find.Test_OpenGL_libs.test_gl) ... skipped 'lib_gl not available'
test_gle (test.test_ctypes.test_find.Test_OpenGL_libs.test_gle) ... skipped 'lib_gle not available'
test_glu (test.test_ctypes.test_find.Test_OpenGL_libs.test_glu) ... skipped 'lib_glu not available'
test_shell_injection (test.test_ctypes.test_find.Test_OpenGL_libs.test_shell_injection) ... ok

Specifically:

test_find_library_with_gcc (test.test_ctypes.test_find.FindLibraryLinux.test_find_library_with_gcc) ... ok
CPython versions tested on:

3.14

Operating systems tested on:

Linux

Linked PRs
  • gh-151231

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First steps

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by running python3 -mtest -v test_ctypes.test_find in the reported Linux environment and focus on test_ctypes.test_find.FindLibraryLinux.test_find_library_with_gcc. Check why this test reports ok without gcc, then verify that its result correctly reflects compiler availability and that the focused test passes with the intended behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
linux, python
Domain
operating-systems, testing-qa
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
25/100

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