> 
> Is there a variable for mk.conf that allows setting compiler flags for 

no, I don't think so.

> (really) all pkgs? I understand that CFLAGS etc. are often overridden by 
> individual pkgs' Makefiles, so something acting on the wrapper layer would 
> probably be useful. Maybe a PKGSRC_CFLAGS?

the problem is not having no such variable, the problem is many packages,
as you already say, not  paying attention to such setting.
So I don't think adding another variable will solve anything.
The best, IMO, would be to have more packages pay attention to
CFLAGS, LDFLAGS, CPPFLAGS, CXXFLAGS set by pkgsrc. This for many
packages does require some tweaking. I don't think adding another variable
would make the job any easier.


-- 
Georg Schwarz    http://home.pages.de/~schwarz/
 georg.schwarz@freenet.de  +49 178 8545053