the latest iris unstable requires ogre1.6,
the ogre packet in ubuntu and debian repos is over a year old and a ogre1.4 version.
So users will have to compile ogre from source, unless someone will make a new ogre1.6 package.
I have no clue about packaging stuff, and no idea where to ask about this, anyone reading on this forum willing to help getting things rolling ?
a few links i got from piet in irc, that might help :
http://wiki.debian.org/Games
https://alioth.debian.org/projects/pkg-games/
https://alioth.debian.org/mail/?group_id=30862
http://packages.debian.org/sid/libogremain-1.4.9