$ git clone -n https://src.fedoraproject.org/rpms/ghc-hxt-unicode.git /var/lib/mock/f40-build-2075000-49451/root/chroot_tmpdir/scmroot/ghc-hxt-unicode
Cloning into '/var/lib/mock/f40-build-2075000-49451/root/chroot_tmpdir/scmroot/ghc-hxt-unicode'...
$ git fetch origin 1b397fce5f0bfa96c2248f0fa2d4a1d9922d51a2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-hxt-unicode
 * [new ref]         1b397fce5f0bfa96c2248f0fa2d4a1d9922d51a2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1b397fc bump release