Thank you, now ruby-ffi compiled fine on ppc64el as shown in the following build log:
https://buildd.debian.org/status/fetch.php?pkg=ruby-ffi&arch=ppc64el&ver=1.9.6debian-2&stamp=1413238408 -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

