Any a.out users?

[Ian Lepore]

On Fri, 2020-03-13 at 13:04 -0400, Ed Maste wrote:
> While looking at other things we came across ldconfig's a.out
> support,
> which hasn't been used by anything in the FreeBSD base system in ~2
> decades.
> 
> I know there are (or at least recently were) folks using a.out
> binaries on contemporary FreeBSD. Most likely statically linked
> proprietary software. I'd be curious to know if anyone is still using
> this.
> 
> As far as ldconfig goes I don't see the value in generating a.out
> hints; if someone is using a.out shared libraries (from FreeBSD 2.x)
> it seems that they can also just use FreeBSD 2.x ldconfig to generate
> the hints file. Is there any reason we shouldn't deprecate ldconfig
> a.out support?

Could a.out support be a kernel config option that's off by default? 
And could its presence be indicated via sysctl in some way, so that
ldconfig could do a.out hints only if support for them is available?

-- Ian