$ git clone -n https://src.fedoraproject.org/rpms/rpc2.git /var/lib/mock/f45-build-34651-690/root/chroot_tmpdir/scmroot/rpc2
Cloning into '/var/lib/mock/f45-build-34651-690/root/chroot_tmpdir/scmroot/rpc2'...
$ git fetch origin de478266d3315bbd5e13d239c5ba6912f417727b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rpc2
 * [new ref]         de478266d3315bbd5e13d239c5ba6912f417727b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at de47826 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild