$ git clone -n https://src.fedoraproject.org/rpms/c4core.git /var/lib/mock/f39-build-1456291-32921/root/chroot_tmpdir/scmroot/c4core
Cloning into '/var/lib/mock/f39-build-1456291-32921/root/chroot_tmpdir/scmroot/c4core'...
$ git fetch origin 4c497c7a57e30870a8a3271227fa9644f411c6bc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/c4core
 * [new ref]         4c497c7a57e30870a8a3271227fa9644f411c6bc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4c497c7 Fix wrong multilib library paths in .cmake files (fix RHBZ#2223194)