bpo-46933: Make pwd module optional (GH-31700)

[tiran]

https://bugs.python.org/issue46933

[erlend-aasland]

Hm, for some reason, configure now decides not to build pwd on my Mac, thus breaking posixpath.expanduser for my username:

$ python3.11
Python 3.11.0a5 (v3.11.0a5:c4e4b91557, Feb  3 2022, 14:54:01) [Clang 13.0.0 (clang-1300.0.29.30)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import posixpath
>>> posixpath.expanduser("~erlendaasland")
'/Users/erlendaasland'
>>> ^D
$ ./python.exe                 
Python 3.11.0a5+ (heads/no-pwd-dirty:a6ca976941, Mar  6 2022, 00:31:10) [Clang 13.0.0 (clang-1300.0.29.30)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import posixpath
>>> posixpath.expanduser("~erlendaasland")
'~erlendaasland'
>>> ^D

getpwuid and getpwuid_r are both available, so I don't see why.

$ grep getpwuid config.cache
ac_cv_func_getpwuid=${ac_cv_func_getpwuid=yes}
ac_cv_func_getpwuid_r=${ac_cv_func_getpwuid_r=yes}

[erlend-aasland]

Aaaah, I see it!

cpython/configure.ac

Lines 6465 to 6466 in 6927632

	AS_CASE([$py_stdlib_not_available],
	[*$1*], [modstate=n/a],

cpython/configure.ac

Line 6378 in 6927632

[Darwin/*], [py_stdlib_not_available="ossaudiodev spwd"],

[erlend-aasland]

We need to use m4_foreach_w (or m4_map_args_w) in PY_STDLIB_MOD and PY_STDLIB_MOD_SIMPLE when checking py_stdlib_not_available for unavailable modules. There may be a more elegant solution.

[tiran]

We need to use m4_foreach_w (or m4_map_args_w) in PY_STDLIB_MOD and PY_STDLIB_MOD_SIMPLE when checking py_stdlib_not_available for unavailable modules. There may be a more elegant solution.

I tried m4_set_add_all but it didn't work like I hoped. The m4 set functions seem to get evaluated during autoconf. We need to evaluate them when configure is running.

[erlend-aasland]

The m4 set functions seem to get evaluated during autoconf. We need to evaluate them when configure is running.

Yeah, I tried some experiments with the m4 wrappers yesterday, but they didn't work out.

[tiran]

Yeah, I tried some experiments with the m4 wrappers yesterday, but they didn't work out.

We may have to restructure the test. I have a working solution, will clean it up and push it later today.

[erlend-aasland]

Yep, this approach works swell. Tested on my mac; all good. I left some comments nits; do with them as you please :)