[HACKERS] Inadequate traces in TAP tests

If you look at this failure case
<https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=jacana&dt=2017-03-19%2000%3A00%3A18>
you see:
   t/002_pg_dump.........1..4449   # Looks like your test died before it could output anything.   dubious       Test
returnedstatus 255 (wstat 65280, 0xff00)   DIED. FAILED tests 1-4449       Failed 4449/4449 tests, 0.00% okay
 


That's really not helpful. We have no idea where things went wrong.

ISTM that the test setup and breakdown code, both in individual tests
and in PostgresNode.pm  should be liberally sprinkled with diag() calls
to make it easier to narrow down errors..

Thoughts?

cheers

andrew

-- 
Andrew Dunstan                https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services