Albe Laurenz <laurenz(dot)albe(at)wien(dot)gv(dot)at> writes:
> Once you can reproduce the problem, try a network trace on the communication
> between cleint and server. Maybe that helps to solve the problem.
Actually, if you can reproduce the problem on demand, try attaching to
the backend process with gdb and setting a breakpoint at errfinish().
The stack trace from there would probably be pretty informative about
where/why the failing conversion is being attempted.
regards, tom lane