$ git clone -n https://src.fedoraproject.org/rpms/byaccj.git /var/lib/mock/f40-build-2208851-52141/root/chroot_tmpdir/scmroot/byaccj
Cloning into '/var/lib/mock/f40-build-2208851-52141/root/chroot_tmpdir/scmroot/byaccj'...
$ git fetch origin ad9f419bad5907c5dbb762645c97d8b4d23ca9cc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/byaccj
 * [new ref]         ad9f419bad5907c5dbb762645c97d8b4d23ca9cc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ad9f419 Drop javapackages test plan