Pip defaults to python implementation when installing protobuf

[David Fernandez Gonzalez]

When installing protobuf with pip in Bionic, pip seems to install the python implementation instead of the cpp implementation. This was not happening before.

$ pip install protobuf==3.17.3 --no-cache-dir
$ python -c "from google.protobuf.internal import api_implementation; print(\"default implement: {}, acl implement: {}\".format(api_implementation._default_implementation_type, api_implementation.Type()))"

it will show: default implement: python, acl implement: python
and it should show: default implement: cpp, acl implement: cpp

[David Fernandez Gonzalez (litios)]

The issue was due to backporting the wheel regex instead of the upstream pip regex for wheels parsing. The backport from upstream pip regex seems to fix the issue.

A new update has been released:

https://ubuntu.com/security/notices/USN-5821-4
python-pip - 9.0.1-2.3~ubuntu1.18.04.8