Caching, docs

[anielsen]

I am trying to figure out how caching works. I am building Dotnet multistage images.

I don't think the paragraph below makes sense. How do I cache the path?

caches

Caching can be enabled by caching the cache path on the task:

https://github.com/concourse/oci-build-task#caches

[ericb-summit]

Yeah, I'm not getting this either. I've enabled caches

          caches:
          - path: cache

and run the same build, on the wame worker, and though the layer SHA are identical, it's still doing a build. So either I'm not getting something or it just doesn't work. Is there some additional magic I need to do to persist the cache folder across builds on the same worker?

[ei-grad]

Maybe related to #87