libwrap is 32bit only
Illumos does not provide a 64bit libwrap and it looks like the reason is because it currently uses sys_errlist and sys_nerr which are only available in 32bit libc. I've attached the patch I use in StormOS which changes libwrap to use strerror and adds a 64bit version in the hope that it will be helpful.
Updated by Andrew Stormont about 7 years ago
I don't think this is going to work as you expect because strerror does not alter errno. Your code will always return "Unknown [UNIX ]error". It's worth noting that strerror will return "Unknown error" if the errno is not recognised. I felt this was acceptable and that's why the original patch is like it is. I'm happy to see that someone cares enough about this to contribute though.
Updated by Alexander Pyhalov about 7 years ago
I'm not sure, but man strerror says:
Upon successful completion, strerror() returns a pointer to
the generated message string. Otherwise, it sets errno and
returns a pointer to an error message string. It returns the
string "Unknown error" if errnum is not a valid error