Problems when syncing todo/tasks to nextcloud with syncevolution

[Merlijn Wajer]

Hi,

I am seeing an issue when synchronising my tasks from my Maemo Tablet to 
my nextcloud instance. I am using syncevolution git HEAD - which is 
really just 2.0.0 with my build-time fix included.

I have set up the synchronisation as follows:

> syncevolution --configure \
>               --template webdav \
>              username=NEXTCLOUD-USER-HERE \
>              password=NEXTCLOUD-PASS-HERE \
>              syncURL=MAIN-DAV-URL-HERE \
>              target-config at nextcloud

> 
> syncevolution --configure \
>               --template webdav \
>              database=TASKS-URL-HERE \
>              backend=caldavtodo \
>              target-config at nextcloud nextcloudtodo


> 
> syncevolution --configure \
>              sync=two-way \
>              backend=maemo-tasks \
>              database= \
>              nextcloud nextcloudtodo

An initial synchronisation went ok, as there were no tasks. When I now 
run this:

> syncevolution --sync two-way nextcloud nextcloudtodo


I get HTTP 415 (unsupported media type or format) errors from nextcloud. 
When looking at my nextcloud log, I find this error (hidden in some 
larger JSON log with no other relevant info):

> Validation error in iCalendar: The value type (DATE or DATE-TIME) must be identical for DUE and DTSTART
Searching on the web I found this comment 
(https://github.com/nextcloud/server/issues/7771#issuecomment-361598094) 
which seems to indicate this is a problem in the implementation in 
syncevolution?

Are there any additional logs that I could gather to help narrow down 
where the issue occurs, assuming this is a syncevolution problem?

Regards,
Merlijn