$ git clone -n https://src.fedoraproject.org/rpms/ghc-servant.git /var/lib/mock/f40-build-744849-111851/root/chroot_tmpdir/scmroot/ghc-servant
Cloning into '/var/lib/mock/f40-build-744849-111851/root/chroot_tmpdir/scmroot/ghc-servant'...
$ git fetch origin bf9865e0f4c57d371a14f71f55e01744c0e084a9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-servant
 * [new ref]         bf9865e0f4c57d371a14f71f55e01744c0e084a9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bf9865e bump release