$ git clone -n https://src.fedoraproject.org/rpms/worker.git /var/lib/mock/f45-build-38484-724/root/chroot_tmpdir/scmroot/worker
Cloning into '/var/lib/mock/f45-build-38484-724/root/chroot_tmpdir/scmroot/worker'...
$ git fetch origin f22f35199816ae320459b66320333a27945c64a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/worker
 * [new ref]         f22f35199816ae320459b66320333a27945c64a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f22f351 drop ix86 support