$ git clone -n https://src.fedoraproject.org/rpms/pem.git /var/lib/mock/f45-build-21518-586/root/chroot_tmpdir/scmroot/pem
Cloning into '/var/lib/mock/f45-build-21518-586/root/chroot_tmpdir/scmroot/pem'...
$ git fetch origin 884b3325c7287c5e6def178a713aa58580358058:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pem
 * [new ref]         884b3325c7287c5e6def178a713aa58580358058 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 884b332 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild