This function is missing on some platforms:
NetBSD 3.0, HP-UX 11.23, IRIX 6.5, Solaris 9, mingw.
@item
-glibc has an incompatible version of this function. The POSIX compliant code
+glibc and Cygwin have an incompatible version of this function. The
+POSIX compliant code
@smallexample
char *s = (strerror_r (err, buf, buflen) == 0 ? buf : NULL);
@end smallexample
@item
When this function fails, it returns -1 and sets @code{errno}, instead of
returning the error number, on some platforms:
-glibc 2.8 with @code{-D_POSIX_C_SOURCE=200112L}, AIX 6.1, OSF/1 5.1.
+glibc 2.12 with @code{-D_POSIX_C_SOURCE=200112L}, AIX 6.1, OSF/1 5.1.
@item
This function does not support the error values that are specified by POSIX
but not defined by the system, on some platforms: