[results, follow-up] Re: 5.3R cvsup failure, libm.so.2. COMPATfiles missing?

[dev tree]

I asked about how to get cvsup working on 5.3-R AMD64.
Mucho thanks for the quick responses, guys.  Additional
comments/questions below.

>>  Steve Kargl wrote:
>>> vi /etc/libmap.conf
>>> libm.so.2  libm.so.3

[my comments for this post]
Adding the lib-mapping worked just fine.  The update with
cvsup was no problem after that.  (and it all built fine, too, see?)
   # uname -a
   FreeBSD inoxidable.tex-an.net 5.3-RELEASE-p2 FreeBSD 5.3-RELEASE-p2 #0:
   (this was on a tyan 2882 w/4GB and 2 Opteron 244 procs)

Chris Howells responded:
>> However that is a really bad idea in the long term so it should be 
>> removed after you have cvsup'd the sources and rebuilt cvsup so that it 
>> uses libm.so.3 instead.

[my comments for this post]
It's always a good idea to remind people to keep track of detrius.

but:
Steve responded back:
> Have you looked at net/cvsup/Makefile.
[...]
> NO_BUILD=       binary-only

> Note the original post specifically mentions AMD64.

[my comments/questions for this post]
So, I don't have the source to rebuild it with libm.so.3.
I'll have to remember about getting rid of the libmap.conf
entry at some point.  Or,  do I really?  Is there anything
that would be screwed up if it was expecting libm.so.2
and it got redirected to libm.so.3 instead?  Is there full
backward compatibility?  Or would I even care, since nothing
else is likely to be asking for libm.so.2 on AMD64, anyway?

And lastly, a follow on question.  If I want to move up to
-current, do a want RELENG6, HEAD, or what?  People seem
to be refering to it as HEAD, but I don't know if that is
what is used for the tag in the cvsup supfile.