why opencv Python package doesn't provide python3dist(opencv-python) ?

[Sérgio Basto]

Hi,
Can someone help me ? 
https://src.fedoraproject.org/rpms/opencv/blob/rawhide/f/opencv.spec
have py_provides but 
https://bugzilla.redhat.com/show_bug.cgi?id=2054951

Thank you . 
-- 
Sérgio M. B.

[Miro Hrončok]

On 18. 02. 22 1:37, Sérgio Basto wrote:
>  Hi,
>  Can someone help me ?
>  https://src.fedoraproject.org/rpms/opencv/blob/rawhide/f/opencv.spec
>  have py_provides but
>  https://bugzilla.redhat.com/show_bug.cgi?id=2054951 
Hi Sérgio,

for some reason, you message ended in my Spam box. Sorry for a delayed response.

First of all, %py_provides has nothing to do with python3dist(opencv-python) 
Provides.

%py_provides takes a given *alternative* name (such as python3-opencv) and 
turns it into other names (such as python-opencv and python3.10-opencv). On a 
package already named python3-opencv, you don't need to use %py_provides, it 
does nothing.

OTOH python3dist(opencv-python) would only be generated if the package actually 
provided a Python opencv-python package, in a Python sense. I.e. when you dnf 
install python3-opencv and run "pip list", do you see opencv-python listed? If 
you do, but the python3dist(opencv-python) provide is missing, there is  bug in 
our generators. If you don't see opencv-python listed, the package MUST NOT 
provide python3dist(opencv-python). The provide literally means "Python tools 
will consider this package is opencv-python".

Looking at the linked bugzilla, it seems to me that the package provides no 
Python metadata at all, only the importable module:

/usr/lib64/python3.10/site-packages/cv2.cpython-310-x86_64-linux-gnu.so

In order to provide the actual metadata you would need to create and install 
dist-info/egg-info directory.

However, it appears to me that the opencv-python package is actually 
https://github.com/opencv/opencv-python and not what we are shipping in Fedora 
as python3-opencv.

This is a weird variant of a missing dependency. In Fedora, we don't package 
opencv-python at all. Packages that require python3dist(opencv-python) have a 
missing dependency. But that dependency can be technically substituted by our 
pytohn3-opencv package, however that requires patching the dependent package 
not to require opencv-python and instead add the dependency for python3-opencv 
on the RPM level manually.

Alternatively, we could package opencv-python to Fedora and patch it to require 
and use python3-opencv, to avoid bundling/duplication.

Either way, there is no easy solution, this is where the Python ecosystem 
clashes with the RPM ecosystem instead of cooperating.

-- 
Miro Hrončok
-- 
Phone: [phone]
IRC: mhroncok