Questions[unison](ubuntu)

I have two machines running Ubuntu. One runs Ubuntu 18.04 LTS and the other one runs Ubuntu 20.04 LTS. I want to use unison to sync files between them. I've installed unison on both of them the conventional way. I.e.:

sudo apt install unison-all

When I check what version is installed, I get this on both machines:

unison version 2.48.4

When I try to sync between them, the sync fails and I get the message:

Fatal error during unmarshaling (input value:ill-formed message) possibly because client and serer have been compiled with different versions of OCaml compiler.

When I look at /usr/bin/unison-2.48.4 on both machines, I get:

3377264 Oct 31  2017 /usr/bin/unison-2.48.4 [18.04]
3866920 Feb 16 10:04 /usr/bin/unison-2.48.4 [20.04]

So while the version number is the same, they have different sizes and a different timestamps, and my guess is that the difference is what causing the error.

The problem is also posted here: https://www.mail-archive.com/[email protected]/msg5750379.html – but no solution yet.

The unison that is installed on the machine running Ubuntu 18.04 LTS syncs fine with unison 2.48.4 for MS Windows 10, so that is the one I want to use on Ubuntu 20.04 LTS as well.

Is there any way to install the version of unison available for Ubuntu 18.04 LTS on Unison 20.04 LTS?

If "yes", how?

I have a folder music on my HDD and folder Music in external HDD. I want these 2 folders to be synced (ie if I add/remove/edit something in one folder, the changes immediately reflects in another).

I think that Unison could do this but I'm struggling setting Unison to sync automatically. For now, I have to manually sync.

I've read that repeat=watch should do the thing but I can't set it.

As you can see the value "watch" hasn't been saved.

I tried nano ~/.unison/Music\ HDD\ EXT\ HDD.prf and manually set repeat = watch and tried to put some file into one folder but it didn't copied it into another.

Do you have any ideas?

I'm running Ubuntu 14.04, when trying to sync a directory with unison using the option repeat=watch. The directory contains ~125K files but I'm abutting a limit on the number of files unison can handle. This is the error I receive:

Fatal error: Server: Filesystem watcher error: cannot add a watcher: system limit reached.
The watcher can be disabled by setting preference 'watch' to false.

I searched for more information by running unison with debug=all but these are the only lines I can find related to the error.

Any idea as to what system settings need to be changed to get around this limit?

I have installed Unison to sync data between my two PCs but I am getting an error about a non existing file. Here it is there is no such file in the .unison folder called lkb60...... which is being complained.

How can I exclude all the svn metadata while synchronizing with unison?

So that all subfiles/folders are also ignored!

Thank you for you help