The configuration script doesn't recognize the correct pthread flag on solaris.

"-pthread" is not supported for gcc/solaris. Instead the correct flag should be "-pthreads"

The compilation test

gcc -std=gnu99 -o conftest -02 -pthread confttest.c >&5

produces an error message

gcc: unrecognized option '-pthread'

but returns 0 so the configuration script doesn't recognize the wrong flag.

simple solution¶

Changing the flag order in acx_pthread_flags (configure; line 23475)

from

acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags" 

to

acx_pthread_flags="-pthreads -pthread pthread -mt $acx_pthread_flags"