Re: [Evolution] Deadly Upgrade

[Matthew Barnes <mbarnes redhat com>]

On Sun, 2010-11-28 at 18:11 -0500, Paul Smith wrote:
> Just as a counterpoint, I upgraded from 2.30 to 2.32 on my Ubuntu 10.10
> system (although I used my own build of 2.32, not the PPA) and all my
> data was migrated successfully and reappeared in its expected new
> location.  It appears there was something unique (or at least not
> common) about your system.  It would be great if we could figure out
> what that was but it seems unlikely at this point.
>
> It's very surprising that data was removed; the migration consists
> basically of directory renames; nothing is removed during the migration
> as I understand it.  I wonder if Matt has any thoughts about this.

I think I know what happened to Kip.  He probably upgraded Evolution to
2.32 and started it, but the Evolution-Data-Server processes from 2.30
were still running, and they still look for data in ~/.evolution.  And
once that mismatch occurs, it leaves a bit of a mess behind which has to
be cleaned up manually by the user.  (I'm glossing over a few technical
details here, but that's basically the problem.)

While it's too late to fix the upgrade path from 2.30 to 2.32 since 2.32
is already out the door, I'm lining up more D-Bus API changes for E-D-S
3.0 and so I recently posted my thoughts on the hackers list about how
to avoid a repeat of this issue.  Basically, I suggested we start
versioning the D-Bus interfaces similar to the way we version shared
library interfaces.  That way, when you upgrade Evolution and launch the
new version, the calendar and address book backend processes will have
to be respawned if the D-Bus interface has changed since the previous
version, and that should avoid the client / backend process mismatch.

http://mail.gnome.org/archives/evolution-hackers/2010-November/msg00041.html

Hope this sheds some light on things.