$ git clone -n https://src.fedoraproject.org/rpms/arianna.git /var/lib/mock/f39-build-1512456-35565/root/chroot_tmpdir/scmroot/arianna
Cloning into '/var/lib/mock/f39-build-1512456-35565/root/chroot_tmpdir/scmroot/arianna'...
$ git fetch origin 63967e0438b0d6203e684e9bc2198145527579a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/arianna
 * [new ref]         63967e0438b0d6203e684e9bc2198145527579a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 63967e0 fix: adjust autosetup command