Introducing some "global" build out-of-source variable

[Ryan Schmidt]

On Mar 24, 2018, at 02:00, Mojca Miklavec wrote:

> Another question just popped up in one of the tickets: "When does base
> create ${configure.dir} and ${build.dir}?" I believe the answer is
> never, but I believe half of the problem could probably be solved if
> all a port needed to do was
> 
>    configure.dir ${workpath}/build
> 
> and then build.dir would also point to ${configure.dir} automatically
> and both would be created automatically when not existing. (There
> might be undesired side effects, I don't know, at this point I don't
> want to claim that this is necessarily a good idea, just a thought.)

Since MacPorts base does not currently know about out-of-source builds, it assumes the build occurs inside the source directory, which should exist after extracting, so I don't think MacPorts currently makes any attempts to create the configure/build directory.


> One particular port tried to use
> 
>    configure.dir ${workpath}/build
>    build.dir ${configure.dir}
>    pre-configure {
>        file mkdir ${configure.dir}
>    }
> 
> which failed because the PortGroup was already expecting
> ${configure.dir} to exist as it did something else with it in its own
> pre-configure step (which gets executed before the one specified in
> the port), so the workaround was to use the pretty counter-intuitive
> 
>    post-patch {
>        file mkdir ...
>    }

I agree that's not ideal.


> But some build systems require it,

Meson? So its portgroup takes care of doing that.


> I don't know what our muniversal PG is doing ...

It's supposed to support both in-source and out-of-source builds.