$ git clone -n https://src.fedoraproject.org/rpms/marker.git /var/lib/mock/f45-build-18037-507/root/chroot_tmpdir/scmroot/marker
Cloning into '/var/lib/mock/f45-build-18037-507/root/chroot_tmpdir/scmroot/marker'...
$ git fetch origin a49cb4cda62ad386a9f919f6b8e8bc7a86d6bbdb:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/marker
 * [new ref]         a49cb4cda62ad386a9f919f6b8e8bc7a86d6bbdb -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a49cb4c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild