configure chokes on pthreads (HPUX, OpenLinux)

[Jonathan B Ellis <ellis@et.byu.edu>]

I'm trying to compile OpenLDAP 1.1.1 for HP-UX 10.20 and OpenLinux 1.3.

On OpenLinux I had to "export CPPFLAGS='-D_MIT_POSIX_THREADS'" before
running configure.  After I did that, the results are substantially
the same:

...
checking POSIX thread version... draft4
checking for LinuxThreads... no
checking for pthread_create... no
checking for pthread_create with -pthread... no
checking for pthread_create with -pthreads... no
checking for pthread_create with -thread... no
checking for pthread_join in -lpthread... no
checking for pthread_join in -lpthreads... no
checking for pthread_create in -lpthread... no
checking for pthread_create in -lc_r... no
checking for pthread_create in -lpthreads... no
checking for pthread_create() in HP-UX -lpthread... yes
checking for sched_yield... no
checking for pthread_yield... no
checking for sched_yield in -lrt... no
checking for sched_yield in -lposix4... no
configure: warning: could not locate sched_yield() or pthread_yield()
configure: error: POSIX Threads are not usable
[from the HP]

...
checking for pthread.h... yes
checking for sched.h... yes
checking POSIX thread version... unknown
configure: error: unknown pthread version
[from the PC]

Any ideas as to where I could find how to proceed, for either platform?

-Jonathan