cfreactor cannot be imported

[exarkun]

>>> from twisted.internet import cfreactor
/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/zope/__init__.py:1: UserWarning: Module twisted was already imported from twisted/__init__.pyc, but /System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python is being added to sys.path
  __import__('pkg_resources').declare_namespace(__name__)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/exarkun/Projects/Twisted/trunk/twisted/internet/cfreactor.py", line 24, in <module>
    from twisted.internet.selectreactor import _NO_FILENO, _NO_FILEDESC
ImportError: cannot import name _NO_FILENO

[glyph]

Looks like #4539 is the culprit. Why don't we have a failing buildbot?

[exarkun]

Because ImportError gets turned into a skip automatically for the reactor builder tests.

[glyph]

I guess I meant it as a rhetorical question.

Put more directly: one aspect of this fix should be a platform-specific "this should always run" thing which tells the OS X slaves to puke if they can't import this reactor for any reason.

[glyph]

Regression, so: highest priority. I would just revert the other change but it looks like an important bugfix for its own right.

[glyph]

And it needs to be completed before 11.1.

[glyph]

I guess I'll take it over.

[exarkun]

(In [31936]) Branching to 'cfreactor-import-5088'

[itamar]

Anything else that needs to be done before this can go into review, other than adding a newsfile? This is only remaining blocker for 11.1.

[exarkun]

​Build results.

[glyph]

Thanks for turning the crank. Land it.

[glyph]

I filed #5216 to try to improve the reactor builder tests so we won't see something like this again.

[exarkun]

(In [32411]) Merge cfreactor-import-5088

Author: exarkun Reviewer: glyph Fixes: #5088

Fix a bad import in cfreactor which caused it to be unusable. Also fix the call-fileno-after-removal behavior which #4539 fixed for the other reactors.