buildmakejobs 0 by default to allow parallel builds

[Rainer Müller]

Ryan Schmidt wrote:
> Why don't we set buildmakejobs to 0 by default in the macports.conf?  
> Setting it to 0 makes MacPorts set the number of make jobs to the  
> number of processors or processor cores. Currently, we default  
> buildmakejobs to 1, meaning software is not built in parallel.

+1
Sounds reasonable in my opinion.

> We already require individual ports to declare "use_parallel_build  
> yes" in order to get parallel building. So any ports that say  
> "use_parallel_build yes" have been specifically tested and found to  
> work in a parallel build environment. So why don't we allow users to  
> benefit from this out of the box? I would expect that many users  
> don't even know they can speed up their builds by changing  
> buildmakejobs.

As use_parallel_build was introduced, I was in favor of making 
'use_parallel_build yes' the default as it still required you to set the 
number of parallel processes you want to use. But as we now have to flag 
every individual port for parallel building, using 'buildmakejobs 0' is 
a good solution to bring this feature to all people.

> On my system, I also set buildnicevalue to 1, instead of the current  
> default of 0, so that other tasks on my computer are still snappy  
> while MacPorts is building something. IMHO something nonzero would be  
> a better default value for buildnicevalue.

I even use 'buildnicevalue 10' as I mostly run build jobs in the background.


But be aware that macports.conf is not updated automatically and we have 
no mechanism to update it, so this will only be useful for new 
installations.

Rainer