$ git clone -n https://src.fedoraproject.org/rpms/ghc-fgl.git /var/lib/mock/f41-build-side-1-2672301-29195/root/chroot_tmpdir/scmroot/ghc-fgl
Cloning into '/var/lib/mock/f41-build-side-1-2672301-29195/root/chroot_tmpdir/scmroot/ghc-fgl'...
$ git fetch origin eaa310422e83237f0c0d2934f77d71bc0730cdaa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-fgl
 * [new ref]         eaa310422e83237f0c0d2934f77d71bc0730cdaa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at eaa3104 https://hackage.haskell.org/package/fgl-5.8.2.0/changelog