Error in pickle using cProfile

[ErickFonseca]

BPO	24676
Nosy	@birkenfeld, @serhiy-storchaka
Superseder	bpo-9914: trace/profile conflict with the use of sys.modules[name]

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

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GitHub fields:

assignee = None
closed_at = <Date 2015-07-21.05:52:20.828>
created_at = <Date 2015-07-20.22:23:56.556>
labels = ['type-bug', 'library']
title = 'Error in pickle using cProfile'
updated_at = <Date 2015-07-21.05:52:20.827>
user = 'https://bugs.python.org/ErickFonseca'

bugs.python.org fields:

activity = <Date 2015-07-21.05:52:20.827>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = True
closed_date = <Date 2015-07-21.05:52:20.828>
closer = 'serhiy.storchaka'
components = ['Library (Lib)']
creation = <Date 2015-07-20.22:23:56.556>
creator = 'Erick Fonseca'
dependencies = []
files = []
hgrepos = []
issue_num = 24676
keywords = []
message_count = 3.0
messages = ['247006', '247010', '247013']
nosy_count = 3.0
nosy_names = ['georg.brandl', 'serhiy.storchaka', 'Erick Fonseca']
pr_nums = []
priority = 'normal'
resolution = 'duplicate'
stage = None
status = 'closed'
superseder = '9914'
type = 'behavior'
url = 'https://bugs.python.org/issue24676'
versions = ['Python 2.7', 'Python 3.4', 'Python 3.5', 'Python 3.6']

[ErickFonseca]

cPickle raises a PicklingError when trying to pickle an instance of a class defined in a module being profiled with cProfile.

Example code:

    import cPickle

    class A(object):
        pass

    a = A()
    with open('file.dat', 'wb') as f:
        cPickle.dump(a, f)

Running the above example with python -m cProfile resulted in

cPickle.PicklingError: Can't pickle <class '__main__.A'>: attribute lookup __main__.A failed

I'm not sure if this is the intended behavior (I suppose __main__ in this case refers to the cProfile module file), but I googled it and couldn't find anything. I noticed this problem in Ubuntu 14.04 and Windows 8.1, both with Python 2.7.

[serhiy-storchaka]

The same is with profile, pickle and in 3.x. May be profile should set sys.modules['__main__']?

[serhiy-storchaka]

This looks as duplicate of bpo-9914.