Bug#904817: lintian: Warn that depending on both Python 2 and Python 3 interpreters is unusual, likely a mistake?

[Stuart Prescott <stuart@debian.org>]

Package: lintian
Version: 2.5.94
Severity: wishlist

Dear Maintainer,

In the upload of translate-toolkit 2.3.0-3, I ended up with the following:

Depends: python3, python3-pkg-resources, python3-six, python3-translate, python3:any, python:any

such that the package depended on both the Python 2 and Python 3 interpreters.
It is unlikely that this is desired (and was not in this case!). My mistake
was that there was one script that still had a #!/usr/bin/python even though
everything had supposedly been converted to Python 3.

Variants of python/python:any/python2.7/python2.7:any mixed with variants of
python3/python3:all/python3.x/python3.x:any are likely to be incorrect.

(Perhaps there are indeed legitimate use cases for this that I haven't
imagined and consulting d-python@ might be sensible.)

cheers
Stuart