$ git clone -n https://src.fedoraproject.org/rpms/mrack.git /var/lib/mock/f45-build-19228-543/root/chroot_tmpdir/scmroot/mrack
Cloning into '/var/lib/mock/f45-build-19228-543/root/chroot_tmpdir/scmroot/mrack'...
$ git fetch origin 2dac72d282dfb125dbfd88cf54f8f01d277b5366:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mrack
 * [new ref]         2dac72d282dfb125dbfd88cf54f8f01d277b5366 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2dac72d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild