$ git clone -n https://src.fedoraproject.org/rpms/libtirpc.git /var/lib/mock/f45-build-17124-496/root/chroot_tmpdir/scmroot/libtirpc
Cloning into '/var/lib/mock/f45-build-17124-496/root/chroot_tmpdir/scmroot/libtirpc'...
$ git fetch origin 9f6a3bf2ab0a7893579833c7688fb68f8ae19251:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libtirpc
 * [new ref]         9f6a3bf2ab0a7893579833c7688fb68f8ae19251 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9f6a3bf Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild