Linux/i386 compat on Freebsd/amd64 / ONLY_FOR_ARCHS

Hello,

This is a repost of a mail I sent to ports_at_ 3 weeks ago. I apologize if 
that bothers anyone, but it didn't generate any replies, and the issue 
remains unsolved.

I've successfully managed to get Linux/i386 compatibility working on 
FreeBSD 5.3/amd64. Took some fiddling, but was actually less complicated 
that I assumed. I've written a short HOWTO, it's available here: 
http://forums.bsdnexus.com/viewtopic.php?t=297

Now, one thing I noticed is that pretty much all linux ports are marked 
with ONLY_FOR_ARCHS=i386, when in fact they work just fine on 
FreeBSD/amd64 (with the linux/i386 compatibility environment, ie 
linux_base-8 installed). This is somewhat annoying,as it requires 
manually setting MACHINE_ARCH=i386 and sometimes ARCH=i386 with every 
make.

Now... I assume that eventually FreeBSD will also get Linux/*64 support 
sooner or later, and that there'll be linux ports that use only one of 
the two linux compat environments.

So what I'm trying to say is that I'm not sure that setting ONLY_FOR_ARCHS 
for binary linux ports makes a lot of sense... could it not be assumed 
that if the linux/i386 compatibility environment is installed on a 
machine, linux/i386 apps will work even if this is not an i386 machine? 
Same thing when FreeBSD gets linux/*64 support.

Unfortunately, I'm not familiar enough with the internals of the ports 
system to come up with an ingeniously simple but powerful solution (nor 
am I ingenious enough ;) ), but maybe I can start a discussion that leads 
to something good?

Benjamin