Peter Geoghegan <pg(at)heroku(dot)com> writes:
> I came up with a simple approach to conveniently attaching a debugger
> when a bug manifested itself from within the regression tests, by
> patching Postgres. This worked quite well. The backend would look for
> the occurrence of a magical token within each and every query string.
If your approach involves modifying a target query in a regression test,
it really seems unnecessary to do all this. Just insert something like
"select pg_sleep(60)" into the test script before the target query.
A variant is to insert a sleep() in the C code, in someplace you don't
expect will be reached except in the problematic cases.
regards, tom lane