Unpickleable ModuleImportError in unittest patch not backported to 2.7

[RachelTobin]

BPO	31297
Nosy	@pitrou, @zware

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2020-04-27.04:10:24.214>
created_at = <Date 2017-08-28.23:53:15.179>
labels = ['type-bug', 'library']
title = 'Unpickleable ModuleImportError in unittest patch not backported to 2.7'
updated_at = <Date 2020-04-27.04:10:24.213>
user = 'https://bugs.python.org/RachelTobin'

bugs.python.org fields:

activity = <Date 2020-04-27.04:10:24.213>
actor = 'zach.ware'
assignee = 'none'
closed = True
closed_date = <Date 2020-04-27.04:10:24.214>
closer = 'zach.ware'
components = ['Library (Lib)']
creation = <Date 2017-08-28.23:53:15.179>
creator = 'Rachel Tobin'
dependencies = []
files = []
hgrepos = []
issue_num = 31297
keywords = []
message_count = 3.0
messages = ['300969', '300998', '367386']
nosy_count = 3.0
nosy_names = ['pitrou', 'zach.ware', 'Rachel Tobin']
pr_nums = []
priority = 'normal'
resolution = 'out of date'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue31297'
versions = ['Python 2.7']

[RachelTobin]

When running the unittest runner in parallel with an module import error present in your code, this exception is raised:

_pickle.PicklingError: Can't pickle <class 'unittest.loader.ModuleImportFailure'>: attribute lookup ModuleImportFailure on unittest.loader failed

unittest should be raising standard exceptions instead.

This was fixed in Python 3.4 with this patch: https://bugs.python.org/issue22903

Given that 2.7 is still supported, this patch should be backported.

[pitrou]

I'm guessing the backport may end up non-trivial. Do you want to try submitting a PR for it?

[zware]

With 2.7 now EOL, I'm closing the issue.