@item
This header file does not define @code{struct timeval} on some platforms:
OSF/1 4.0.
+@item
+This header file is not self-contained --- it requires @code{<string.h>}
+before @code{FD_ZERO} can be used --- on some platforms:
+Solaris 10.
@end itemize
Portability problems not fixed by Gnulib: