@item
This function has an incompatible declaration on some platforms:
Solaris 11 2010-11 (when @code{_POSIX_PTHREAD_SEMANTICS} is not defined).
+@item
+This function returns a truncated result, instead of failing with error code
+@code{ERANGE}, when the buffer is not large enough, on some platforms:
+OSF/1 5.1.
@end itemize
Portability problems not fixed by Gnulib:
@itemize
+@item
+This function fails even when standard input is a tty on some platforms:
+HP-UX 11.11.
+@item
+This function fails with error code @code{EINVAL} instead of @code{ERANGE} when
+the second argument is zero on some platforms:
+HP-UX 11.31.
@end itemize