$ git clone -n https://src.fedoraproject.org/rpms/tvlsim.git /var/lib/mock/f40-build-800595-143605/root/chroot_tmpdir/scmroot/tvlsim
Cloning into '/var/lib/mock/f40-build-800595-143605/root/chroot_tmpdir/scmroot/tvlsim'...
$ git fetch origin 973ddbe2d74f65781ab5ba1d4f19decc3d6540a5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/tvlsim
 * [new ref]         973ddbe2d74f65781ab5ba1d4f19decc3d6540a5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 973ddbe Upstream upgrade