[New-bugs-announce] [issue18963] test_selectors test_above_fd_setsize cases fail on OS X due to infinite hard limit

[Ned Deily]

New submission from Ned Deily:

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ERROR: test_above_fd_setsize (test.test_selectors.PollSelectorTestCase)
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Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/support/__init__.py", line 485, in wrapper
    return func(*args, **kw)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/test_selectors.py", line 312, in test_above_fd_setsize
    resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))
ValueError: current limit exceeds maximum limit

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ERROR: test_above_fd_setsize (test.test_selectors.KqueueSelectorTestCase)
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Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/support/__init__.py", line 485, in wrapper
    return func(*args, **kw)
  File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/test/test_selectors.py", line 312, in test_above_fd_setsize
    resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))
ValueError: current limit exceeds maximum limit

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Ran 58 tests in 8.080s

FAILED (errors=2, skipped=12)

Looking at the OS X man page for setrlimit(2), it appears the test's strategy of trying to set the soft RLIMIT_NOFILE to the hard RLIMIT_NOFILE ceiling will fail on OS X (at least) if the hard limit is infinite:

>>> import resource
>>> resource.getrlimit(resource.RLIMIT_NOFILE)
(2560, 9223372036854775807)

>From the man page:
COMPATIBILITY
     setrlimit() now returns with errno set to EINVAL in places that historically
     succeeded.  It no longer accepts "rlim_cur = RLIM_INFINITY" for RLIM_NOFILE.
     Use "rlim_cur = min(OPEN_MAX, rlim_max)".

https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man2/setrlimit.2.html

----------
components: Tests
messages: 197189
nosy: ned.deily, neologix
priority: normal
severity: normal
stage: needs patch
status: open
title: test_selectors test_above_fd_setsize cases fail on OS X due to infinite hard limit
versions: Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue18963>
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