$ git clone -n https://src.fedoraproject.org/rpms/python-cramjam.git /var/lib/mock/f40-build-783858-133120/root/chroot_tmpdir/scmroot/python-cramjam
Cloning into '/var/lib/mock/f40-build-783858-133120/root/chroot_tmpdir/scmroot/python-cramjam'...
$ git fetch origin 5bbaf014cf31ee878ca16a30c8cb3b3a1f6562f8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-cramjam
 * [new ref]         5bbaf014cf31ee878ca16a30c8cb3b3a1f6562f8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5bbaf01 Initial package (close RHBZ#2257285)