# Checks for header libraries functions.
CHECK_LIBRARY_EXISTS(dl dlopen "" HAVE_DLOPEN_IN_LIBDL)
CHECK_LIBRARY_EXISTS(execinfo backtrace "" HAVE_BACKTRACE_IN_LIBEXECINFO)
-CHECK_LIBRARY_EXISTS(pthread pthread_create "" pthread)
+CHECK_LIBRARY_EXISTS(pthread pthread_create "" HAVE_PTHREAD)
+
+if (NOT HAVE_PTHREAD)
+ message(FATAL_ERROR "You must have a working pthread installation to proceed.")
+endif()
+
CHECK_LIBRARY_EXISTS(pthread sem_init "" HAVE_SEM_INIT_LIB)
CHECK_LIBRARY_EXISTS(pthread sem_open "" HAVE_SEM_OPEN_LIB)
CHECK_LIBRARY_EXISTS(pthread sem_timedwait "" HAVE_SEM_TIMEDWAIT_LIB)