$ git clone -n https://src.fedoraproject.org/rpms/php-sebastian-diff6.git /var/lib/mock/f40-build-1465188-23640/root/chroot_tmpdir/scmroot/php-sebastian-diff6
Cloning into '/var/lib/mock/f40-build-1465188-23640/root/chroot_tmpdir/scmroot/php-sebastian-diff6'...
$ git fetch origin a9e47a028d401b34259cac0c4ebc315656898e0c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/php-sebastian-diff6
 * [new ref]         a9e47a028d401b34259cac0c4ebc315656898e0c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a9e47a0 v6.0.2