@item
This header file is missing on some platforms:
mingw, BeOS.
+@item
+@code{struct sched_param} is not defined on some platforms:
+Haiku.
+@item
+@code{SCHED_FIFO}, @code{SCHED_RR}, @code{SCHED_OTHER} are not defined on
+some platforms:
+Haiku.
@end itemize
Portability problems not fixed by Gnulib: