ctypes.util.test() calls cdll.load, which LibraryLoader does not have

[tony-CloseAI]

Bug report

ctypes.util.test() calls cdll.load(...), which LibraryLoader does not have, so the self-test raises on Windows.

Where: Lib/ctypes/util.py, test() (line 535 on main), the Windows branch:

if os.name == "nt":
    print(cdll.msvcrt)
    print(cdll.load("msvcrt"))

LibraryLoader defines LoadLibrary, not load, and its __getattr__ turns the unknown name into an AttributeError.

Reproduce (Windows, 3.13.5; the line is the same on main, whose util.py already needs 3.15 syntax to import):

> python -c "import ctypes.util; ctypes.util.test()"
<CDLL 'msvcrt', handle 7ffd0a0b0000 at 0x...>
AttributeError: load

Proposed fix:

-        print(cdll.load("msvcrt"))
+        print(cdll.LoadLibrary("msvcrt"))

Checked by running test() on Windows against 3.13.5's util.py: the current code raises AttributeError: load; the fixed code completes and prints the loaded CDLL.

Environment: Windows 11, CPython 3.13.5.

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Found while auditing installed code with a verification tool I am building; the reproduction above was run on the version named, and the proposed fix was applied to a local copy and run as well. Report drafted with AI assistance.

Linked PRs

• gh-157763: Fix ctypes.util.test() on Windows #157770
• gh-157763: Soft-deprecate ctypes.util.test #157776

[ZeroIntensity]

I think it would be better to just soft-deprecate this rather than try to support it as a public API.

[tony-CloseAI]

Soft-deprecating it sounds right to me: test() is a leftover self-test rather than something worth supporting as a public API.

If it should keep working until it goes, cdll.LoadLibrary("msvcrt") is the whole change - I ran test() on Windows with it and the function completes. Happy to send either patch, the one-liner or the deprecation, whichever you prefer; equally happy to leave this here as a record if you would rather not touch the function before it is removed.

[kumaraditya303]

Why keep it at all? There is no value in keeping broken stuff, it can be removed directly.

[ZeroIntensity]

I don't think it can be safely removed without a deprecation period (it works on some platforms; that's enough for it to exist somewhere in production). We could do one, but that would arguably be more of a burden than just soft-deprecating it.