avoiding multiple PIP packages installation

[apatsekin]

Hey guys! A bit confused on how to properly set a PIP dependency for my package if it depends on OpenCV. README clearly states:

There are four different packages (see options 1, 2, 3 and 4 below) and you should SELECT ONLY ONE OF THEM.

implying
opencv-python
opencv-contrib-python
opencv-python-headless
opencv-contrib-python-headless

Say I have opencv-contrib-python-headless installed in my environment, and then I install pip package that depends on opencv-python-headless. Even though it can perfectly fine work with (and supposed to) opencv-contrib-python-headless, pip still gonna install opencv-python-headless breaking aforementioned rule.

How to handle that? What should that package set as a dependency to install opencv only if neither packages installed

[alalek]

There is Provides-Dist, but Python package managers doesn't support it yet.

Some discussion is here: opencv/opencv#21611

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Current workaround - after install remove unused package variants.

[dcnieho]

Shouldn't Obsoletes-Dist also be used, so that installing, e.g. opencv-contrib-python leads to opencv-python being removed if it was already there. Well, it would only in theory since neither of these fields is supported.

[dcnieho]

I have added this to a relevant discussion, in the hope it may get picked up.