$ git clone -n https://src.fedoraproject.org/rpms/ghc-gtk.git /var/lib/mock/f41-build-851044-165853/root/chroot_tmpdir/scmroot/ghc-gtk
Cloning into '/var/lib/mock/f41-build-851044-165853/root/chroot_tmpdir/scmroot/ghc-gtk'...
$ git fetch origin b02b4c7e8dbc8d286ae119659e00fed98f3da714:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-gtk
 * [new ref]         b02b4c7e8dbc8d286ae119659e00fed98f3da714 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b02b4c7 https://hackage.haskell.org/package/gtk-0.15.9/changelog