This has been a huge support burden for us. I seriously considered doing
this in 3.0 but caved to a vocal minority and the desire to keep as much
backwards compatibility as possible. At this point, however, I'm done
witnessing the abuse Anthony has to suffer over this and I'm done with
the undue hostility that people who don't bother to read the docs
display. Hopefully, this eases that a bit.
Since Flake8 3.0 we've had the ability for plugins to use
`extend_default_ignore` to register codes they want disabled by default.
This, however, was a permanent disabling unfortunately. Our code didn't
have a way of understanding that this new set of `ignore` codes was
actually the 'default' set for that run. Much like the
extended_select_list, we now attach extended_ignore_list to be able to
confidently determine if the ignore we get in the DecisionEngine is
actually the Default Ignore list and what plugins what us to ignore by
default.
Refs https://github.com/PyCQA/pep8-naming/pull/157
Implement `--extend-select` command line argument following what was
done for `--extend-ignore` in !233. This option can be used to
selectively add individual codes without overriding the default list
entirely.
Addresses the remaining item of issue #1061.
Platforms such as Termux on Android, and other exotic devices
do not provide a sem_open implementation on the OS level. This
is problematic, as the error resulting from this occurs when
calling multiprocessing.Pool, throwing an unhandled ImportError.
The issue itself is outlined in https://bugs.python.org/issue3770.
This change allows devices missing this system call to respond
to the missing feature by falling back to synchronous execution,
which appears to be the default behaviour if the multiprocessing
module is not found.
This change also adds a potential fix for developers working
on platforms where multiprocessing itself cannot be imported.
The existing code would set the name referencing the import to
None, but there are no clear checks to ensure this does not
result in an AttributeError later when multiprocessing.Pool
has accession attempts.
Existing users should see no difference in functionality, as they
will assumably already be able to use flake8, so will not be
missing this sem_open call.
Users on devices without the sem_open call will now be able
to use flake8 where they would be unable to before due to
unhandled ImportErrors.
