$ git clone -n https://src.fedoraproject.org/rpms/obs-service-extract_file.git /var/lib/mock/f45-build-20411-570/root/chroot_tmpdir/scmroot/obs-service-extract_file
Cloning into '/var/lib/mock/f45-build-20411-570/root/chroot_tmpdir/scmroot/obs-service-extract_file'...
$ git fetch origin 692a2ac36d515042ab68d1ee8db97e77046e8793:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/obs-service-extract_file
 * [new ref]         692a2ac36d515042ab68d1ee8db97e77046e8793 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 692a2ac Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild