+JsonEncodeDateTime(char *buf, Datum value, Oid typid)
...
+ elog(ERROR, "unknown jsonb value datetime type oid %d", typid);
I think this should be %u.
commit cc4feded0a31d2b732d4ea68613115cb720e624e
Author: Andrew Dunstan <andrew(at)dunslane(dot)net>
Date: Tue Jan 16 19:07:13 2018 -0500
Centralize json and jsonb handling of datetime types