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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[`ctypes`][`linux`] `ctypes.util.find_library()` crash instead of return None","articleBody":"# Bug report\r\n\r\n### Bug description:\r\n\r\n# The problem:\r\n\r\n`ctypes.util.find_library()` raises an exception on certain inputs when it cannot find it.\r\n\r\n# Expected behavior:\r\n\r\nNo exception, return `None` as [advertised](https://docs.python.org/3/library/ctypes.html#ctypes.util.find_library) if it cannot find the library.\r\n\r\n# Reproducer:\r\n```python\r\n# on python 3.10, but same deal on other versions too\r\n\u003e\u003e\u003e import ctypes.util\r\n\u003e\u003e\u003e ctypes.util.find_library('libgomp')\r\nTraceback (most recent call last):\r\n  File \"\u003cstdin\u003e\", line 1, in \u003cmodule\u003e\r\n  File \"/path/to/lib/python3.10/ctypes/util.py\", line 351, in find_library\r\n    _get_soname(_findLib_gcc(name)) or _get_soname(_findLib_ld(name))\r\n  File \"/path/to/lib/python3.10/ctypes/util.py\", line 148, in _findLib_gcc\r\n    if not _is_elf(file):\r\n  File \"/path/to/lib/python3.10/ctypes/util.py\", line 100, in _is_elf\r\n    with open(filename, 'br') as thefile:\r\nFileNotFoundError: [Errno 2] No such file or directory: b'liblibgomp.a'\r\n```\r\nNote that the crash does not occur if you put nonsense in:\r\n1. `find_library('asdadsas')` -\u003e OK\r\n2. `find_library('libasdasdasd')` -\u003e OK\r\n\r\nThe problem appears to be a bit more contrived. Python is attempting to parse the output from gcc, which in this case is:\r\n```\r\n/usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/Scrt1.o\r\n/usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/crti.o\r\n/usr/lib/gcc/x86_64-linux-gnu/12/crtbeginS.o\r\n/usr/bin/ld: cannot find -llibgomp: No such file or directory\r\n/usr/bin/ld: note to link with /usr/lib/gcc/x86_64-linux-gnu/12/libgomp.a use -l:libgomp.a or rename it to liblibgomp.a\r\n/usr/lib/gcc/x86_64-linux-gnu/12/libgcc.a\r\n/usr/lib/gcc/x86_64-linux-gnu/12/libgcc_s.so\r\n/usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/libgcc_s.so.1\r\n/usr/lib/gcc/x86_64-linux-gnu/12/libgcc.a\r\ncollect2: error: ld returned 1 exit status\r\n```\r\nBut then the parser is getting confused trying to parse the useful diagnostic message mentioning `libgomp.a`.\r\n\r\nMachine details (from `platform.uname()`)\r\n```\r\nuname_result(system='Linux', node='iblis', release='6.5.0-14-generic', version='#14~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Mon Nov 20 18:15:30 UTC 2', machine='x86_64')\r\n```\r\n\r\n### CPython versions tested on:\r\n\r\n3.10, 3.11, 3.12\r\n\r\n### Operating systems tested on:\r\n\r\nLinux\n\n\u003c!-- gh-linked-prs --\u003e\n### Linked PRs\n* gh-114394\n* gh-114444\n* gh-114445\n\u003c!-- /gh-linked-prs --\u003e\n","author":{"url":"https://github.com/Jacobfaib","@type":"Person","name":"Jacobfaib"},"datePublished":"2024-01-18T18:35:34.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/114257/cpython/issues/114257"}