Comment 5 for bug 857824

While people wouldn't often need 2.32 AND 2.40 together, they may well require one of the two because unison will only work if it is the same version on both computers that are being synchronised.

Hence, at present, if one of those computers is running Oneiric and the other is running Precise, you can't use Unison to sync between them unless you install Unison version 2.32 on the machine running Precise, hence missing out on the significant improvements with version 2.40, AND not being able to sync with other machines running Precise unless they also downgrade Unison.

I'll look at the Backports stuff and see what I can do.