joblib: FTBFS: AttributeError: Can't pickle local object 'test_parallel_pickling.<locals>.g'

Imported from Debian bug http://bugs.debian.org/802106:

Source: joblib
Version: 0.8.3-1
Severity: serious
Justification: fails to build from source
Tags: sid stretch
User: <email address hidden>
Usertags: ftbfs
X-Debbugs-CC: <email address hidden>

Dear Maintainer,

The package fails to build:

Check that MemmapingPool uses /dev/shm when possible ... ok
Check that large arrays are not copied in memory in return ... ok
Check that memmaps with a bad buffer are returned as regular arrays ... ok
Doctest: joblib ... ok

======================================================================
ERROR: Check that pmap captures the errors when it is passed an object
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/nose/case.py", line 198, in runTest
    self.test(*self.arg)
  File "/joblib-0.8.3/joblib/test/test_parallel.py", line 172, in test_parallel_pickling
    (delayed(g)(x) for x in range(10))
  File "/usr/lib/python3.5/unittest/case.py", line 727, in assertRaises
    return context.handle('assertRaises', args, kwargs)
  File "/usr/lib/python3.5/unittest/case.py", line 176, in handle
    callable_obj(*args, **kwargs)
  File "/joblib-0.8.3/joblib/parallel.py", line 652, in __call__
    for function, args, kwargs in iterable:
  File "/joblib-0.8.3/joblib/test/test_parallel.py", line 172, in <genexpr>
    (delayed(g)(x) for x in range(10))
  File "/joblib-0.8.3/joblib/parallel.py", line 120, in delayed
    pickle.dumps(function)
AttributeError: Can't pickle local object 'test_parallel_pickling.<locals>.g'

======================================================================
FAIL: Check that name collisions with functions will raise warnings
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/nose/case.py", line 198, in runTest
    self.test(*self.arg)
AssertionError: 7 != 1
    '7 != 1' = '%s != %s' % _common_shorten_repr(7, 1)
    '7 != 1' = self._formatMessage('7 != 1', '7 != 1')
>> raise self.failureException('7 != 1')

======================================================================
FAIL: Check that name collisions with functions will raise warnings
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/nose/case.py", line 198, in runTest
    self.test(*self.arg)
AssertionError: False is not true
    'False is not true' = self._formatMessage('False is not true', "%s is not true" % safe_repr(False))
>> raise self.failureException('False is not true')

...

FAILED (errors=1, failures=5)
debian/rules:25: recipe for target 'python-test3.5' failed
make[1]: *** [python-test3.5] Error 1

Full build log:
https://reproducible.debian.net/rb-pkg/unstable/amd64/joblib.html

-- System Information:
Debian Release: stretch/sid
APT prefers unstable
APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)