+OpenBSD 4.0, OSF/1 5.1, NonStop Kernel, Cygwin 1.5.x, mingw.
+@item
+This function reports failure for @code{strerror(0)} (by setting
+@code{errno} or using a string similar to out-of-range values),
+although POSIX requires this to leave @code{errno} unchanged and
+report success, on some platforms:
+FreeBSD 8.2, OpenBSD 4.7, MacOS X 10.5.