$ git clone -n https://src.fedoraproject.org/rpms/mgarepo.git /var/lib/mock/f40-build-2610839-63893/root/chroot_tmpdir/scmroot/mgarepo
Cloning into '/var/lib/mock/f40-build-2610839-63893/root/chroot_tmpdir/scmroot/mgarepo'...
$ git fetch origin f378d9da793564b1bbbd183419d28e8dd2e829a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mgarepo
 * [new ref]         f378d9da793564b1bbbd183419d28e8dd2e829a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f378d9d Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild