Purely for convenience and to avoid opening cans of worms, it might be
acceptable to provide locking with pkgsrc to prevent two convcurrent
package makings happening at once (eg, any make in a pkg creates a
lockfile that any otehr attempted makes block on), then making
dependencies in paarallel.

Eg, each package can compile however it sees fit, using internal
parallelism only if the distfile makefile specifies it.

I often compile lots of packages at once, but currently have to manually
make sure there are no intersecting dependencies, because running two
makes on the same source tree at once causes a mess :-)

ABS

-- 
                               Alaric B. Snell
 http://www.alaric-snell.com/  http://RFC.net/  http://www.warhead.org.uk/
   Any sufficiently advanced technology can be emulated in software