`test_posix_fallocate()` fails under `test_posix` under WASI

[brettcannon]

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ERROR: test_posix_fallocate (__main__.PosixTester.test_posix_fallocate)
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Traceback (most recent call last):
  File "/Lib/test/test_posix.py", line 405, in test_posix_fallocate
    posix.posix_fallocate(fd, 0, 10)
OSError: [Errno 58] Not supported

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Detected with WASI-SDK 20 and wasmtime 14.

Linked PRs

• GH-111804: Drop posix.fallocate() under WASI #111869
• [3.12] GH-111804: Drop posix.fallocate() under WASI (GH-111869) #111919
• [3.11] GH-111804: Drop posix.fallocate() under WASI (GH-111869) #111920

[brettcannon]

I have asked at https://bytecodealliance.zulipchat.com/#narrow/stream/219900-wasi/topic/Who.20is.20expected.20to.20make.20.60posix_fallocate.60.20work.3F to find out who I should reach out to for finding out what this function errors out.

[brettcannon]

Turns out posix_fallocate() was in WASI preview1, but has been yanked in preview2 due to inconsistent semantics across OSs. Best solution then is to just skip posix_fallocate() on WASI unconditionally.

[brettcannon]

Fixed in main, but the backports to 3.11 and 3.12 still need to be done.