Re: pgsql: Replace our hacked version of ax_pthread.m4 with latest upstream

I wrote:
> Heikki Linnakangas <heikki.linnakangas@iki.fi> writes:
>> Replace our hacked version of ax_pthread.m4 with latest upstream version.

> Well, in fact that did not work.  See gharial: it appears to have picked
> the wrong thread flags.

And even more annoying, now that I've git pull'd, I find it's also broken
the build on my RHEL6 box:

../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
make[3]: *** [pg_ctl] Error 1
make[2]: *** [all-pg_ctl-recurse] Error 2
make[2]: *** Waiting for unfinished jobs....
../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
make[3]: *** [pg_receivexlog] Error 1
make[3]: *** Waiting for unfinished jobs....
../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
make[3]: *** [pg_basebackup] Error 1
../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
make[3]: *** [pg_recvlogical] Error 1
make[2]: *** [all-pg_basebackup-recurse] Error 2
../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
make[3]: *** [pg_dumpall] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: *** [pg_rewind] Error 1
make[2]: *** [all-pg_rewind-recurse] Error 2
../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
make[3]: *** [pg_restore] Error 1
../../../src/interfaces/libpq/libpq.so: undefined reference to `pthread_sigmask'
collect2: ld returned 1 exit status
make[3]: *** [pg_dump] Error 1
make[2]: *** [all-pg_dump-recurse] Error 2
make[1]: *** [all-bin-recurse] Error 2
make: *** [all-src-recurse] Error 2

It appears the new improved macro doesn't bother with -pthread at all.
Previously I got this in Makefile.global:

PTHREAD_CFLAGS                =   -pthread  -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS
PTHREAD_LIBS          =  -lpthread

Now I get

PTHREAD_CFLAGS                =  -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS
PTHREAD_LIBS          =

and that simply doesn't work.  I do not know why the buildfarm isn't
entirely red, but I'm dead in the water.  Please revert this.

            regards, tom lane