[SyncEvolution] "Comparison was impossible" "

[Patrick Ohly]

On Mon, 2017-05-01 at 17:15 +0200, Vincent Lambert wrote:
> Le 28/04/2017 à 11:36, Patrick Ohly a écrit :
> > On Fri, 2017-04-28 at 10:18 +0100, Graham Cobb wrote:
> > > On 28/04/17 10:05, Patrick Ohly wrote:
> > > > On Fri, 2017-04-28 at 10:31 +0200, Vincent wrote:
> > > > > Could you tell me more about synccompare?
> > > > In the syncevolution.org packages, it is under /usr/bin/synccompare.
> > > > It's a perl script that takes two database dumps and compares them,
> > > > similar to a diff between text files.
> > > I find it to be of variable usefulness. It is great when it works, but
> > > in my experience it scales horribly.
> > I just use it on a laptop and it works for me, but I agree that it's
> > mostly a hack originating in the automated testing. There's even a bug
> > open for rewriting it...
> > 
> > > I think I always see "comparison was impossible" with refreshes. I
> > > assumed that is because the databases are deleted or something (although
> > > thinking about it further I am not sure that is a reasonable expectation).
> > There should be "before" and "after" dumps also for refreshes, so this
> > has to be something else.
> > 
> 
> So what is the goal of this command?

It's purely informational. It's not needed for the sync to work.

> I deleted the two related to my configuration, restarted to clear the
> sessions and then added again my notes taken from there
> http://influence-pc.fr/03-07-2015-synchroniser-ses-contacts-et-calendrier-dubuntu-phone-via-owncloud-cosy-cloud (was working from past 2 years) so just after the first "sync slow" here is what I can see:

So was this a slow sync or a refresh-from-remote sync?

> Changes applied during synchronization:
> +---------------|-----------------------|-----------------------|-CON-+
> |               |       @default        |       @owncloud       | FLI
> |
> |        Source | NEW | MOD | DEL | ERR | NEW | MOD | DEL | ERR | CTS
> |
> +---------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> |      contacts |  0  |  1  |  0  |  0  |  0  |  0  |  0  |  0  |  0
> |
> |      slow, 0 KB sent by client, 44 KB received
> |
> |      140 item(s) matched
> |
> |      item(s) in database backup: 140 before sync, 140 after it
> |
> +---------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> |          start Mon May  1 16:47:48 2017, duration 0:13min
> |
> |               synchronization completed successfully
> |
> +---------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> 
> Data modified @default during synchronization:
> *** @default/contacts ***
> Comparison was impossible.
> 
> 
> Even if I delete the config, the backup database still contain
> entries!

Not the *backup* database. Your local *system* database still has these
140 contacts. Removing the SyncEvolution configuration does not clean
that database, because it exists independently from SyncEvolution.

So for a slow sync, the behavior quoted above is as expected.

A "--sync refresh-from-remote" would tell SyncEvolution to erase the
local contacts before the sync, so all of them then should show up as
"new" on the local side.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.