v3.6.3 has ImportError on Ubuntu 18.04

[jayschwa]

I get ImportError: dynamic module does not define init function (init_cpuid). I do not have a problem with the previous version 3.6.1.

Example:

$ pip install pycryptodomex==3.6.3
$ python -m Cryptodome.SelfTest
Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 174, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/home/jay/.local/lib/python2.7/site-packages/Cryptodome/SelfTest/__main__.py", line 35, in <module>
    SelfTest.run(stream=sys.stdout, verbosity=1, config=config)
  File "/home/jay/.local/lib/python2.7/site-packages/Cryptodome/SelfTest/__init__.py", line 61, in run
    tests = get_tests(config=config)
  File "/home/jay/.local/lib/python2.7/site-packages/Cryptodome/SelfTest/__init__.py", line 82, in get_tests
    from Cryptodome.SelfTest import Cipher; tests += Cipher.get_tests(config=config)
  File "/home/jay/.local/lib/python2.7/site-packages/Cryptodome/SelfTest/Cipher/__init__.py", line 31, in get_tests
    from Cryptodome.SelfTest.Cipher import test_AES;      tests += test_AES.get_tests(config=config)
  File "/home/jay/.local/lib/python2.7/site-packages/Cryptodome/SelfTest/Cipher/test_AES.py", line 29, in <module>
    from Cryptodome.Cipher import AES
  File "/home/jay/.local/lib/python2.7/site-packages/Cryptodome/Cipher/__init__.py", line 36, in <module>
    from Cryptodome.Cipher._mode_gcm import _create_gcm_cipher
  File "/home/jay/.local/lib/python2.7/site-packages/Cryptodome/Cipher/_mode_gcm.py", line 47, in <module>
    from Cryptodome.Util import _cpuid
ImportError: dynamic module does not define init function (init_cpuid)

System info:

$ python --version
Python 2.7.15rc1
$ uname -a
Linux jay-notebook 4.15.0-23-generic #25-Ubuntu SMP Wed May 23 18:02:16 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[Legrandin]

Can you trying explicitly removing version 3.6.1 with pip uninstall pycryptodomex and then do pip install pycryptodomex==3.6.3?

I suspect you have a Cryptodome.Util._cpuid.so hanging around when you install 3.6.3 (and in that version there is a Cryptodome.Util._cpuid.py, which does not get picked up because .so files take precendence).

I guess the new file should have been called differently to avoid this collision...

[jayschwa]

Explicitly removing all versions of the module and reinstalling 3.6.3 works. SelfTest passes.

[dejafait]

I can confirm in my case that a mysterious leftover file .../python3.4/site-packages/Cryptodome/Util/_cpuid.cpython-34m.so was the cause. I am not sure from which older version of pycryptodomex it came from. Maybe 3.4.6.

pip uninstall pycryptodomex did not help, as can be seen on this output:

Uninstalling pycryptodomex-3.6.3:
  Would remove:
    /.../lib/python3.4/site-packages/Cryptodome/*
    /.../lib/python3.4/site-packages/pycryptodomex-3.6.3.dist-info/*
  Would not remove (might be manually added):
    /.../lib/python3.4/site-packages/Cryptodome/Cipher/_errors.py
    /.../lib/python3.4/site-packages/Cryptodome/Util/_cpuid.cpython-34m.so
    /.../lib/python3.4/site-packages/Cryptodome/Util/_galois.cpython-34m.so
    /.../lib/python3.4/site-packages/Cryptodome/Util/_number_new.py
Proceed (y/n)? y
  Successfully uninstalled pycryptodomex-3.6.3

Pip would never remove the 4 files listed as might be manually added. The mystery still holds: where did they come from?

The solution I chose was to drop and recreate from scratch the whole virtualenv to be sure to get rid of all might be manually added files. This way I would also fix at the same time any other leftover issue from other packages.

This issue costed a lot to my project (broke production because the leftover file was mysteriously absent in preproduction only). Lots of investigation and effort. Hopefully this helps other people.