+@item
+This function is missing on some platforms:
+glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8,
+AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin 1.5.x, mingw, MSVC 9, Interix 3.5, BeOS.
+But the replacement function is not safe to be used in libraries and is not multithread-safe.
+@item
+This function fails to reject trailing slashes on non-directories on
+some platforms:
+AIX 7.1, Solaris 11 2011-11.
+@item
+This functions does not support @code{AT_SYMLINK_FOLLOW} on some platforms:
+Linux kernel 2.6.17.