What were you trying to do that didn't work?

I run a local "fedora-like" koji build environment at $dayjob. I just recently (Nov-8) completed mass branching steps for our internal f41 release and noticed that all createrepo tasks for f41 fail due to "Cannot detect compression type" errors in the updates repo.

I have tested against two different external mirrors, leaseweb.net, and facebook.net. The failure exists in both.

What is the impact of this issue to you?

We are unable to build any packages where upstream repomd is compressed with zstd.

Please provide the package NVR for which the bug is seen:

createrepo_c-0.20.1-2.el9

How reproducible is this bug?:

Can be reproduced by manually running mergerepo_c with an upstream repo that contains zstd compressed repo xml files.

Steps to reproduce

1. mergerepo_c -a x86_64 -o ./repo -r https://mirror.facebook.net/fedora/linux/updates/41/Everything/x86_64/
2.  
3.  

Expected results

Success

Actual results

C_CREATEREPOLIB: Critical: cr_metadata_load_xml: Error encountered while parsing Critical: Cannot load repo: "https://mirror.facebook.net/fedora/linux/updates/41/Everything/x86_64/" : Error encountered while parsing:primary.xml parsing: Cannot open /tmp/koji/tasks/465/50465/createrepo_c_tmp_repo_BAZ7wH/repodata/7fc131418a87157ce23f4d4bd6083ab68cdccd81911864b9f5a2d01657ad75cf-primary.xml.zst: Cannot detect compression type