memory leak in update_and_load_enabled_repos() (Python)

[timlau]

It looks like there is some memory there is not released when calling package_sack.update_and_load_enabled_repos(True)
from python when the cache is expired.
I have created some test code located here
https://github.com/timlau/apitest/tree/main/dnf5/memleak

it does some basic dnf5 setup and get the number of updates and clean up the base each time
with a fresh cache it run 3x and memory is released each time.

If I run "dnf5 clean expire-cache" before running the same code, the amount of allocated memory is increased at each run

Tested on dnf5.x86_64 5.1.17-1.fc40

I use python3-memray to track the memory usage

[kontura]

Thanks for the report and for the test code.

I was able to track it down mostly to the use of zchunk in librepo.
If zchunk is turned of (there is an option in dnf.conf) the leaks go away.

I made a couple PRs to improve the situation:
rpm-software-management/librepo#322
zchunk/zchunk#108

[timlau]

Thanks for looking into the issue

[kontura]

The PRs have been merged.
The issue should be resolved.