$ git clone -n https://src.fedoraproject.org/rpms/ghc-singleton-bool.git /var/lib/mock/f38-build-side-42-init-devel-807746-28235/root/chroot_tmpdir/scmroot/ghc-singleton-bool
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-807746-28235/root/chroot_tmpdir/scmroot/ghc-singleton-bool'...
$ git fetch origin 4a7d108864ced5606e8990f980a052f00e4af013:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-singleton-bool
 * [new ref]         4a7d108864ced5606e8990f980a052f00e4af013 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4a7d108 update to 0.1.6