[cfarm-users] AIX portability

[Kaz Kylheku]

On 2022-09-21 02:49, Jonathan Wakely wrote: 
> Well this is just user error. Unless I'm mistaken, _XOPEN_SOURCE=500
> selects a standard that doesn't even define struct in6_addr.

That is almost certainly correct; but the issue reproduces with 700,
which I tried first. Then I found the smallest value for which it
reproduces.

I bumped to 700 in December 2015, which at the time was not in relation
to IPv6 networking, but large file handling: in order to reveal
fseeko and ftello in <stdio.h>. (Most likely it was Glibc's <stdio.h>).

I seem to recall that the 500 value might be quite old, like from
the 1997 SuS.

Oh look; that is still hosted online, indeed, the 500 value is
discussed:

https://pubs.opengroup.org/onlinepubs/007908799/xsh/compilation.html