$ git clone -n https://src.fedoraproject.org/rpms/python-nbclient.git /var/lib/mock/f40-build-2481885-61633/root/chroot_tmpdir/scmroot/python-nbclient
Cloning into '/var/lib/mock/f40-build-2481885-61633/root/chroot_tmpdir/scmroot/python-nbclient'...
$ git fetch origin d3a745160d56e670f42d457d8474b70a5e0dd26c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-nbclient
 * [new ref]         d3a745160d56e670f42d457d8474b70a5e0dd26c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d3a7451 Convert to %autorelease and %autochangelog