[Evolution-hackers] Need help debugging owncloud caldav problem

[James Bottomley <James Bottomley HansenPartnership com>]

At least, it may not necessarily be a caldav problem, I think it might
actually be an ical parsing issue.  The symptoms are that I've exported
about 1,300 events from my google calendar and imported it successfully
into owncloud.  Verification via the web calendar and also the caldav
android connector works and sees all the events.  Evoution does not, its
calendar only sees a couple of them.  doing CALDAV_DEBUG=all, I see the
caldav backend has sync'd all the events, confirmed by this message

        CalDAV - finished syncing with 1278 items in a cache

And a manual inspection of 

.cache/evolution/calendar/1447535993 17449 1 jarvis/calendar.ics

Shows they're all present, including the ones evolution is not
displaying.  I suspect there's some issue somewhere in the ical file
that's causing a parse problem ... so my question, how do I debug this?
Is there a magic debug option to show parsing of ical events?

Thanks,

James