$ git clone -n https://src.fedoraproject.org/rpms/riemann-c-client.git /var/lib/mock/f45-build-34522-687/root/chroot_tmpdir/scmroot/riemann-c-client
Cloning into '/var/lib/mock/f45-build-34522-687/root/chroot_tmpdir/scmroot/riemann-c-client'...
$ git fetch origin 6a93878bbaf4cb0bf6008431fb19bfd93c00ce12:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/riemann-c-client
 * [new ref]         6a93878bbaf4cb0bf6008431fb19bfd93c00ce12 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6a93878 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild