$ git clone -n https://src.fedoraproject.org/rpms/mbuffer.git /var/lib/mock/f40-build-790186-136350/root/chroot_tmpdir/scmroot/mbuffer
Cloning into '/var/lib/mock/f40-build-790186-136350/root/chroot_tmpdir/scmroot/mbuffer'...
$ git fetch origin 3406bc7d53ff4617f5a42d541d9fc9286839a344:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mbuffer
 * [new ref]         3406bc7d53ff4617f5a42d541d9fc9286839a344 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3406bc7 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild