Re: BUG #7816: test for compiler output produces bogus results

seebs@seebs.net writes:
> Your modified acx_pthread.m4 tests for any compiler output to stderr at all,
> and considers it evidence that a flag is invalid.

I believe the reason we do that is that we want to find flags that will
not result in the compiler generating a warning during each and every
source compile.  Most developers would consider such a behavior broken,
and not without good reason.

> This test is not actually correct, although it usually works.

[ shrug... ]  Given the lack of previous complaints, it works 99.999%
of the time, which is about as much reliability as can be hoped for in
most autoconf tests :-(.  I'm afraid we can't help you without breaking
it worse for a larger number of other people.

            regards, tom lane