$ git clone -n https://src.fedoraproject.org/rpms/ghc-fgl.git /var/lib/mock/f40-build-2066265-49280/root/chroot_tmpdir/scmroot/ghc-fgl
Cloning into '/var/lib/mock/f40-build-2066265-49280/root/chroot_tmpdir/scmroot/ghc-fgl'...
$ git fetch origin 12edd5d0750f3f77ac0e6e67044c7a3283caeb8e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-fgl
 * [new ref]         12edd5d0750f3f77ac0e6e67044c7a3283caeb8e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 12edd5d https://hackage.haskell.org/package/fgl-5.8.0.0/changelog