In HP-UX 10.10 and 10.20, only DCE threads are supported, the header of which is found only in /opt/dce/include (it's not in /usr/include). Hence, the only way to #include <pthread.h> on HP-UX 10.10 and 10.20 is to add -I/opt/dce/include to the appropriate compile line (note that the HP-UX 10.20 build at http://tinderbox.mozilla.org/SeaMonkey-Ports/ is failing at this moment in time for this very reason). The solution is to add -I/opt/dce/include to OS_CFLAGS lines in nsprpub/config/HP-UX.mk for HP-UX 10.10 and 10.20. At this moment in time, this means lines 93 and 98, so that the lines 92 to 103 would then read: 92 ifeq ($(OS_RELEASE),B.10.10) 93 OS_CFLAGS += -DHPUX10 -DHPUX10_10 -I/opt/dce/include 94 DEFAULT_IMPL_STRATEGY = _PTH 95 endif 96 97 ifeq ($(OS_RELEASE),B.10.20) 98 OS_CFLAGS += -DHPUX10 -DHPUX10_20 -I/opt/dce/include 99 ifndef NS_USE_GCC 100 OS_CFLAGS += +DAportable +DS1.1 101 endif 102 DEFAULT_IMPL_STRATEGY = _PTH 103 endif You should, of course, make sure that pthread.h is actually present in /opt/dce/include on your build machines :-) BTW, HP no longer support HP-UX 10.10, so no need to worry about it - 10.20 and 11.00 should be the HP-UX platforms you support, with the primary one being 11.00.

In all of our HP-UX 10.x machines with the optional DCE development environment installed, there is a symbolic link /usr/include/pthread.h that points to /opt/dce/include/pthread.h. Is the creation of this symbolic link an installation option, or perhaps it was created manually by the people who installed the DCE development environment on our machines?

I am not sure how you are building on 10.20. But using aCC we found that we can't use DCE threads and instead have to use NSPR threads for the binary to work (Our latest build M16 is up on the mozilla ftp site). However further looking at this bug it is over a year old... the port is now building... I feel that this bug should be closed as Invalid... we should be using NSPR threads for mozilla on 10.20

another 2 years gone, anything new on this one ?

I vote for marking INVALID.

Marked the bug WONTFIX. On HP-UX 10.x, we only support using NSPR threads with Mozilla.