[MacPorts] #25507: kdelibs4 4.4.x fails to compile/link: undefined symbols "_png_set_longjmp_fn"

[Joshua Root]

On 2010-7-10 22:12 , Rainer Müller wrote:
> On 2010-07-10 00:38 , Ryan Schmidt wrote:
>> I once suggested it would be a good idea to replace the
>> "use_parallel_build" yes/no switch with a more fine-grained switch
>> (say "parallel_jobs") where you could specify the maximum number of
>> parallel jobs. "parallel_jobs 1" would then be the equivalent of
>> today's "use_parallel_build no", "parallel_jobs 0" could be the
>> equivalent of today's "use_parallel_build yes" (mirrors the way
>> "buildmakejobs" works in macports.conf today), and for example
>> "parallel_jobs 2" could be used for ports that support 2 parallel
>> jobs but not more. But for now we don't have this, so software must
>> either support any arbitrary number of parallel jobs, or not be run
>> in parallel at all.
> 
> I would prefer the build.* namespace as that is the only phase affected.
> 
> We could use build.jobs in the Portfile to specify a *maximum* number of
> parallel jobs (the minimum of build.jobs and buildmakejobs will be used,
> build.jobs == 0 means unlimited). And then we could also add a
> "build.parallel yes/no" to be able to disable parallel building at all.

Seems kind of overengineered to me. The few ports that have a known safe
build.jobs limit > 1 can just do:

if {${build.jobs} > $safe_limit} {
	build.jobs $safe_limit
}

- Josh