$ git clone -n https://src.fedoraproject.org/rpms/ghc-listsafe.git /var/lib/mock/f39-build-1507131-35226/root/chroot_tmpdir/scmroot/ghc-listsafe
Cloning into '/var/lib/mock/f39-build-1507131-35226/root/chroot_tmpdir/scmroot/ghc-listsafe'...
$ git fetch origin 5bc6724c5bb3be4b42788eba5c90fd4d3a3cf8c1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-listsafe
 * [new ref]         5bc6724c5bb3be4b42788eba5c90fd4d3a3cf8c1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5bc6724 bump release