CCache: Segregating cache directories per port

[Christopher Nielsen]

> On 2020-12-11-F, at 14:16, Chris Jones <jonesc at hep.phy.cam.ac.uk> wrote:
> 
> Just curious, but what exactly is the advantage of doing this ? I am not sure i see what problem you are trying to solve that a single cache causes .
> 
>> On 11 Dec 2020, at 6:20 pm, Christopher Nielsen <mascguy at rochester.rr.com> wrote:
>> 
>> Is it possible to easily override the ccache directory via command-line, with the goal of maintaining separate caches per port?
>> 
>> I did some quick digging through the MacPorts TCL files, and didn’t see support for such an override.
>> 
>> My current solution — workable, though not ideal — is to update ‘ccache_dir’ in ~/.macports/macports.conf. That’s easily doable via a ‘port’ wrapper script.
>> 
>> But assuming I didn’t miss anything, would folks be open to having the ability to specify ‘ccache_dir’ from the port command-line? If so, I’ll contribute the changes.
>> 
>> Thoughts?

In short, I’d like to maintain separate caches for ports I’m working on — Mame being the best example, as it takes at least an hour to build locally — without the cache being flooded by other ports. And preferably without resorting to custom ccache configuration, etc.

Make sense?