>> A fair tradeoff, given that the alternative is no SMP support at all.
>
> I don't think so.
>
> It's more important to speed builds of individual packages,
> rather then speed up builds of package batches. I admit I'm more
> interested in cutting firefox or openoffice (re)build time, rather then
> ability to build many packages faster.
>
> Don't waste time implementing a framework to build several packages
> parallely IMHO. Building individual packages using multiple paralell
> jobs will yield bigger benefit for all pkgsrc users, and not just
> buik builds.

I don't think that these things need to be, or should be, exclusive of one 
another. That'd definitely the wrong idea. Parallel builds of dependencies 
will certainly help with three things: building using multiple machines of 
the same arch in a shared tree, building of packages which cannot be 
safely compiled with parallel jobs in that package, and overall time to 
build exactly the examples you mention - packages like Firefox and 
OpenOffice. See how long it takes to build either of them. Then compare 
that time to the total amount of time it takes to build all of the 
dependencies for them. You'll see how much benefit there could potentially 
be.

John