[Unison-hackers] How do I connect unison-2.12.0 linux to 2.9.1 for solaris?

[Andrew Schulman]

> The current downloads list 2.9.1 for solaris as the latest, but other
> clients are much later.  Is there a way to force a unison-2.12.0 to
> connect to 2.9.1, or are the solaris clients hidden away elsewhere?

Unison doesn't allow you to do this, because the network protocols
change between versions.  Attempting to synchronize using different
versions, supposing that you changed the source code to disable the
sanity check, would result in corrupted data.

In versions of Unison prior to 2.13, if the version numbers didn't match
exactly Unison would halt with an error message.  Starting with 2.13.x,
the second number of the version number changes if and only if there's a
change in the network protocol.  So for example, all 2.13.x versions are
mutually compatible with each other, and incompatible with 2.14.x.

Your best bet for now is to build your own Unison 2.12.0 for Solaris, or
use a 2.9.1 package in Linux.

Good luck,
Andrew.