Issue 33281: ctypes.util.find_library not working on macOS (original) (raw)

On Python 3.7.0a4 and later (including 3.7.0b4), find_library currently always returns None on macOS. It works on 3.7.0a3 and earlier. Tested on macOS 10.11 and 10.13.

Expected result: Tested on 3.6.5, 3.7.0a1 and 3.7.0a3:

from ctypes.util import find_library find_library('iconv') '/usr/lib/libiconv.dylib' find_library('c') '/usr/lib/libc.dylib'

Current output on 3.7.0a4 to 3.7.0b3:

from ctypes.util import find_library find_library('iconv') find_library('c')

On 15/04/2018 07:56, Ned Deily wrote:

Ned Deily <nad@python.org> added the comment:

Thanks for the report and the good detective work! I see the same results. It appears that the error was introduced by c5ae169e1b73315672770517bf51cf8464286c76 for Issue26439. It looks we need both a fix and a test for this. This really needs to be fixed for 3.7.0b4.

Perhaps he can give a bit more info. I do not understand how this could break things, as the darwin code is earlier in the queue.

if os.name == "posix" and sys.platform == "darwin":     from ctypes.macholib.dyld import dyld_find as _dyld_find     def find_library(name):         possible = ['lib%s.dylib' % name,                     '%s.dylib' % name,                     '%s.framework/%s' % (name, name)]         for name in possible:             try:                 return _dyld_find(name)             except ValueError:                 continue         return None

if sys.platform.startswith("aix"):     # AIX has two styles of storing shared libraries     # GNU auto_tools refer to these as svr4 and aix     # svr4 (System V Release 4) is a regular file, often with .so as suffix     # AIX style uses an archive (suffix .a) with members (e.g., shr.o, libssl.so)     # see issue#26439 and _aix.py for more details

    from ctypes._aix import find_library

elif os.name == "posix":     # Andreas Degert's find functions, using gcc, /sbin/ldconfig, objdump     import re, tempfile

    def _findLib_gcc(name):

As I understand the code above (and maybe I am wrong) - the code should be calling the unchanged routines in the macholib subdirectory. A simple test on macOS would be to comment out the two lines

if sys.platform.startswith("aix"):     from ctypes._aix import find_library

That will "delete" the AIX find_library logic.

In other words - can someone check whether the unchanged Lib/ctypes/macholib/* files are being used? And if not, then something surprising is preventing that. If they are - no idea how the macholib code got effected by this. The goal was to have all changes in the _aix.py file, rather than in util.py.

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nosy: +Michael.Felt, ned.deily, vstinner priority: normal -> release blocker stage: -> needs patch

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Python tracker <report@bugs.python.org> <https://bugs.python.org/issue33281>

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