As far as I can tell the only place pthread.h is included or used is in xcb/xcb.h. Because libraries may have grown to depend upon the inclusion it will not be possible to simply remove pthread.h from the header file. However, adding a check for a define (maybe "XCB_NO_INCLUDE_PTHREAD") that disables the inclusion of pthread.h would be backwards compatible. Then perhaps in the far flung future the inclusion of pthread.h could be disabled by default.

This issue is important to me because I am interested in statically analysing my programs and to do so I use a custom set of headers for libc which are specially annotated. Because statically analysing multithreading is really, really hard the headers for pthreads have not been implemented yet and so the static analyser falls back to the system's headers which causes the build to fail. I would like to be able to disable inclusion of pthread.h and so statically analyse my program. Of course, I can use an ugly hack to work around the issue by defining the header guard _PTHREAD_H in my program so the issue is not at all urgent but eventually in the far flung future I'd like to get rid of it. Also, statically analysing a big interface such as a GUI is very hard and not something to bother putting much effort in so this issue is also not important in that way. I feel this should be done eventually though. I feel this issue should be solved eventually though.

This issue will eventually make for very, very, slightly faster build times.