pkg_resources: UnboundLocalError: local variable 'dist' referenced before assignment

[The-Compiler]

When trying to run my package's tests frozen via cx_Freeze on Windows, I just got this:

  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\pkg_resources\__init__.py", line 2986, in _initialize_master_working_set
    del dist
UnboundLocalError: local variable 'dist' referenced before assignment

full traceback:

unittests-frozen runtests: commands[2] | C:\projects\qutebrowser\.tox\unittests-frozen/build/run-frozen-tests
Traceback (most recent call last):
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\cx_Freeze\initscripts\Console.py", line 27, in <module>
    exec(code, m.__dict__)
  File "scripts/dev/run_frozen_tests.py", line 38, in <module>
    pytest_rerunfailures, pytest_warnings]))
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\config.py", line 39, in main
    config = _prepareconfig(args, plugins)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\config.py", line 118, in _prepareconfig
    pluginmanager=pluginmanager, args=args)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 724, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 338, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 333, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 595, in execute
    return _wrapped_call(hook_impl.function(*args), self.execute)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 249, in _wrapped_call
    wrap_controller.send(call_outcome)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\helpconfig.py", line 28, in pytest_cmdline_parse
    config = outcome.get_result()
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 278, in get_result
    raise ex[1].with_traceback(ex[2])
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 264, in __init__
    self.result = func()
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 596, in execute
    res = hook_impl.function(*args)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\config.py", line 861, in pytest_cmdline_parse
    self.parse(args)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\config.py", line 966, in parse
    self._preparse(args, addopts=addopts)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\config.py", line 927, in _preparse
    self.pluginmanager.load_setuptools_entrypoints("pytest11")
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 495, in load_setuptools_entrypoints
    from pkg_resources import iter_entry_points, DistributionNotFound
  File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_and_load
  File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_and_load_unlocked
  File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_unlocked
  File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_backward_compatible
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\pkg_resources\__init__.py", line 2958, in <module>
    @_call_aside
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\pkg_resources\__init__.py", line 2944, in _call_aside
    f(*args, **kwargs)
  File "C:\projects\qutebrowser\.tox\unittests-frozen\lib\site-packages\pkg_resources\__init__.py", line 2986, in _initialize_master_working_set
    del dist
UnboundLocalError: local variable 'dist' referenced before assignment

This seems to be introduced in #698 (cc @minrk) and happens when the for dist in working_set: above doesn't assign to dist because working_set is empty.

[minrk]

Fixed by #703. Sorry about that, and thanks for catching it!

[The-Compiler]

No worries, that was a mean one, probably wouldn't have noticed it either. Thanks for the quick fix!

[destijl]

Thanks for fixing this, just hit it myself. I see that 25.1.2 includes this fix and is tagged on github but isn't released on pypi? If you're expecting to get that onto pypi soon I can probably avoid having to go through all my install scripts pinning the setuptools version. Any idea when that might happen?

[jaraco]

Hmm. PyPI releases are meant to be automatic from tagged versions. Let's see what happened.

Aah, so it built and tests passed, but the upload failed because I forgot to bump the versions in the code (by running bumpversion patch) first.

I'll push out a release momentarily.

[jaraco]

I expect the release to go out with this job.

[destijl]

Great, it's out, thanks!