+are not defined on many platforms:
+glibc 2.3.6, MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX
+5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 8, Cygwin 1.5.x, mingw, Interix 3.5, BeOS.
+
+@item
+@samp{AT_FDCWD} is defined with a value too large for an @code{int} on some
+platforms:
+Solaris 10.