$ git clone -n https://src.fedoraproject.org/rpms/ghc-gtk3.git /var/lib/mock/f41-build-839501-160201/root/chroot_tmpdir/scmroot/ghc-gtk3
Cloning into '/var/lib/mock/f41-build-839501-160201/root/chroot_tmpdir/scmroot/ghc-gtk3'...
$ git fetch origin 5508ca0ebeb4293178b1baec76b08e8cf7853405:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-gtk3
 * [new ref]         5508ca0ebeb4293178b1baec76b08e8cf7853405 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5508ca0 https://hackage.haskell.org/package/gtk3-0.15.9/changelog