Speed up build phase with "make -j"

[Anders F Björklund]

Markus Weissmann wrote:

> No, but we should only enable parallel builds for software we know to 
> behave correctly. I wont kick you if you enable a parallel build for a 
> port that you maintain and you are not 100% sure that it'll work 
> _always_ -- the bug reports are yours. But I do not like 1. 
> unmaintained and 2. my ports to automatically try to build in parallel 
> -- and I suppose there are other maintainers that don't like their 
> ports to get broken, too.
> Therefore I prefer this to be an opt-in and I will enable this feature 
> e.g. for the gcc ports I maintain.

Parallell builds are an optional feature, and will never be disabled by 
default.
If the build breaks, the user can always go back to build as the 
regular -j 1 ?

The only thing for Portfiles is where you *know* that -j doesn't work 
at all,
sorta like violate destroot ? All the others "might" work, just like 
you say...

--anders