$ git clone -n https://src.fedoraproject.org/rpms/ghc-temporary.git /var/lib/mock/f41-build-side-1-2955661-35550/root/chroot_tmpdir/scmroot/ghc-temporary
Cloning into '/var/lib/mock/f41-build-side-1-2955661-35550/root/chroot_tmpdir/scmroot/ghc-temporary'...
$ git fetch origin e16ce2c825695efe0cbc44ecb4dd5d7cded88259:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-temporary
 * [new ref]         e16ce2c825695efe0cbc44ecb4dd5d7cded88259 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e16ce2c bump release