Re: More: Compatibility issues

Thanks for this, Greg, sorry still a few more uncertainties:

I want to move ahead now sticking with Ubuntu 22.04 LTS, as it has taken 
me a long time to configure the master computer and I don't want to 
start again with 24.04 LTS.

I will thus install Ubuntu 22.04 LTS on the second very similar computer 
and make sure that everything syncs between them with 2.51. If I then 
upgrade one (the designated server) to unison 2.53 with ocaml 4.13 I 
will gain better functionality/reliability of the server (and thus the 
whole sync process) without needing to upgrade also the client unison 
package. But if I decide to do an upgrade, it would seem surer and not 
much more complicated to upgrade both machines to 2.53 without worrying 
about ocaml, no?

I am not yet sure whether I will attempt this, but would like to see how 
to actually get the tarball to try (not clear from the site you 
recommend, as I see only one mention of ocaml 4.13 in *build_compat 
(4.13.x)*, and I only see descriptions of the builds and no actual 
tarballs).

Concerning my legacy Ubuntu 18.04 machine with unison 2.48 ocaml 4.05, 
since there is no way that an upgrade on the other machines can sync 
with it, and no easy way to upgrade two or three LTS steps in Ubuntu, I 
will just leave it aside and manually install its unique applications on 
the two newer computers.

Anyway, congratulations on solving the inter-version compatibility 
problem for the future - it's really a GIANT step.

Best regards,

     John


Le 15/02/2024 à 18:16, Greg Troxel a écrit :
>> In the Migration Guide, you speak about Client Versions and Server
>> Versions, but if I understand correctly there is only one unison
>> program which can be installed on the "Server" (the machine initiating
>> the sync) or the "Client" (the machine being remotely called for the
>> sync)?
> There is only one program.  client and server are roles for a particular
> sync.
>
>> If I get 2.52 or 2.53 installed on the server, do I understand that it
>> will be backward compatible with 2.51 or 2.48 installed on the client
>> machine, irrespective of the OCaml version of the client unison,
>> PROVIDED that I regenerate the archives files (your wording is hazy
>> since it says only that "same OCaml version" is needed for
>> interoperability).
> Before 2.52, data structures and wire protocols changed formats when
> ocaml versions changed (usually).
>
> Now, data structures are independent of ocaml versions.
>
> So if you upgrade to 2.53.3 -- or better 2.53.4RC1 -- then you will have
> to regen archive files.  One should always, before any upgrade, get
> everything in sync.
>
> As for interop with 2.48 and 2.51, you will need a 2.53.x with an
> adequately matching ocaml version.
>
> Overall, my take is that 2.48 especially and 2.51 are too old to deal
> with and should be upgraded.  Complaints that packaging systems still
> have them should be directed to those packaging systems.
>
> Go to
>
>    https://urldefense.com/v3/__https://github.com/bcpierce00/unison/actions/runs/7902642581__;!!IBzWLUs!Qf4cxTOXqLXbFk7hVJzt5tbwlTAFkXNFL5CAV14AWVpoZdMr20Jc-_aHRgql_Cn5SgTG5MvL6xSIRhqBaitry2TlpdY$ 
>
> and scroll down.  You'll see artifacts named by OS and ocaml version.
>
>
> Whether ubuntu 22.04 is compatible with 20.04, it's very likely, because
> if not I bet somebody would have said so.  I don't know if ubuntu
> publishes binary compatibility rules, and if so, if they follow them.
> But it looks like our builds now use 22.04 mostly.
>
>
> As for installation, these are tarballs (well they are zip) that contain
> binaries.  You'll have to deal with it manually.   Yes, uninstall the
> package first.
>
>
>
-- 
************

                John B. Rose
                1 Bis rue des Châtre-Sacs
                92310 Sèvres, France

                Email:[email protected]

-- 
To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].