backport unison 2.32.52-1ubuntu2 to lucid

[Andy Whitcroft]

Unison requires the major and minor version numbers to be the same to allow syncing between systems. Currently all older releases have 2.27 and thus cannot sync with maverick:

  $ unison-sync agent57.local git2/.
  Fatal error: Received unexpected header from the server:
   expected "Unison 2.27\n" but received "Unison 2.32\n\000\000\000\000",
  which differs at "Unison 2.3".
  This can happen because you have different versions of Unison
  installed on the client and server machines, or because
  your connection is failing and somebody is printing an error
  message, or because your remote login shell is printing
  something itself before starting Unison.

I have built the Maverick version on Lucid without modification and tested that fixes sync. I have also uploaded this to my staging PPA (where they are currently pending).

[Derek Simkowiak (ubuntu-cool-st)]

This has been an ongoing problem for several years now.

One version of Unison came out with Ubuntu 8.04. When I upgraded some of my workstations to 8.10, suddenly they could not back up to the Unison server (which was on 8.04 LTS). I was forced to upgrade all of my 8.04 LTS servers to a non-official Unison package. And here we are again with 10.04 and 10.10.

The root cause of this headache is that Unison is not backwards compatible between versions. (This is stupid. Unison should be like rsync.) But Ubuntu makes it worse by not offering backports when new releases of Unison come out.

Here is another user with the same problem:

http://ubuntuforums.org/archive/index.php/t-1449670.html

His use-case scenario, using Unison with Macs, Windows, and Linuxes, is also how I use Ubuntu.

Please complain to the Unison maintainers to quit being so pedantic about version number strings, and in the meantime, Ubuntu could start offering regular (zero-day) backports would allow us to do easy upgrades to our older systems.