"pkg: Unable to find catalogs" message during "pkg upgrade" on 10-RC5

[Yuri]

Updating repository catalogue
digests.txz <...skipped...>
packagesite.txz <...skipped...>
Incremental update completed, 21327 packages processed:
1786 packages updated, 1050 removed and 67 added.
pkg: Unable to find catalogs

This last message came without an obvious reason.
Next run of "pkg upgrade" succeeded:
Updating repository catalogue
Nothing to do

So it is some intermittent issue.

Yuri