+@item
+Some platforms declare the function without marking the last two
+parameters @code{const}.
+FreeBSD, Cygwin 1.7.1.
+@end itemize
+
+Portability problems not fixed by Gnulib:
+@itemize
+@item
+This function is missing on some platforms:
+mingw, MSVC 9.
+@item
+After a successful call to @code{openpty}, the application needs to close
+the master's file descriptor before closing the slave's file descriptor,
+otherwise the process may hang in a state where it cannot be killed, on
+some platforms: MacOS X 10.4.11.