$ git clone -n https://src.fedoraproject.org/rpms/hydrogen.git /var/lib/mock/f39-build-1628236-39436/root/chroot_tmpdir/scmroot/hydrogen
Cloning into '/var/lib/mock/f39-build-1628236-39436/root/chroot_tmpdir/scmroot/hydrogen'...
$ git fetch origin 54596212326d7efb9d54d6bfb31a5cc9d4d6909f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/hydrogen
 * [new ref]         54596212326d7efb9d54d6bfb31a5cc9d4d6909f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5459621 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild