Automatic reverse-dependency checks in every Fedora PR

[frenzymadness]

Description

I'm experimenting with a Python tool that takes a component (SRPM) name and a version, analyzes reverse dependencies, and detects whether an upgrade to that version would break something in Fedora (currently rawhide). It takes into account all RPMs produced from that SRPM and all provides of all those RPMs. It works with locally cached repository metadata so it's fast even for thousands of relations between packages. The result looks like this:

$ fedora-revdep-check.py jupyterlab 5
Initializing DNF and loading repository metadata...
Enabled 2 repository/repositories
Loading repository metadata (this may take a moment)...
Repository metadata loaded and cached.

Analyzing impact of updating jupyterlab to version 5...

Found 1 binary package(s) from jupyterlab:
  - jupyterlab-4.5.0-1.fc44

Found 13 unique provides (excluding bundled)

================================================================================
REVERSE DEPENDENCY ANALYSIS
================================================================================
Source Package: jupyterlab
New Version: 5
Binary Packages: jupyterlab-4.5.0-1.fc44

✗ Found 5 potential conflict(s):

  Package: python-ipyparallel-9.0.2-1.fc44
  Issues:
    - Requires: (python3dist(jupyterlab) >= 4 with python3dist(jupyterlab) < 5)
      Failed:   python3dist(jupyterlab) < 5
      New version 5 does not satisfy this requirement

  Package: python-jupyterlab-widgets-3.0.16-1.fc44
  Issues:
    - Requires: (python3dist(jupyterlab) >= 4 with python3dist(jupyterlab) < 5)
      Failed:   python3dist(jupyterlab) < 5
      New version 5 does not satisfy this requirement

  Package: python-nbdime-4.0.2-9.fc44
  Issues:
    - Requires: (python3dist(jupyterlab) < 5~~ with python3dist(jupyterlab) >= 4)
      Failed:   python3dist(jupyterlab) < 5~~
      New version 5 does not satisfy this requirement

  Package: python-notebook-7.5.0-1.fc44
  Issues:
    - Requires: (python3dist(jupyterlab) < 4.6~~ with python3dist(jupyterlab) >= 4.5~rc0)
      Failed:   python3dist(jupyterlab) < 4.6~~
      New version 5 does not satisfy this requirement

  Package: python3-notebook-7.5.0-1.fc44
  Source:  python-notebook
  Issues:
    - Requires: (python3.14dist(jupyterlab) < 4.6~~ with python3.14dist(jupyterlab) >= 4.5~rc0)
      Failed:   python3.14dist(jupyterlab) < 4.6~~
      New version 5 does not satisfy this requirement

================================================================================

We (Python maintenance team) do this check one way or another for almost all our updates to make them safe but not all Fedora maintainers have this habit (or knowledge).
Is it possible to add this as a job to Packit CI and enable it for all pull requests? If so, how can I do it (propose it)?

Importance

Important. I believe it would improve Fedora maintainers' lives a lot.

Workaround

• There is an existing workaround that can be used until this is implemented.

[nforro]

@frenzymadness Do you want to contribute this yourself? It would require writing a TMT test plan that can run in Testing Farm, then it's just a matter of adding it here.

[frenzymadness]

I can try it. I have the core implemented locally. Do you prefer having a hard copy of the helper scripts in the repository, or should I publish it somewhere (PyPI, GitHub, Fedora RPMs) first, so then Packit can install it and use it?

[nforro]

Do you prefer having a hard copy of the helper scripts in the repository, or should I publish it somewhere (PyPI, GitHub, Fedora RPMs) first, so then Packit can install it and use it?

As it will run in Testing Farm, it will have to be cloned/installed from somewhere, both the scripts and the test plan, but it doesn't have to be the same place, you can publish it as a package somewhere and the test plan can be e.g. here: https://github.com/packit/tmt-plans