Also CACHE keyword, for cache mounts. Makes incremental tools like compilers work well in the context of dockerfiles and layer caches.

That can extend beyond just producing docker iamges as well. Under the covers the CACHE keyword is how lib/rust in Earthly makes building Rust artifacts in CI faster.

https://github.com/earthly/earthly/issues/1399

I would add that 1. Earthly is meant for full CI/CD use-cases, not just for image building. We've forked buildkit to make that possible. And 2. remote caching is pretty slow overall because of the limited amount of data you can push/pull before it becomes performance-prohibitive. We have a comparison in our docs between remote runner (e.g. Earthly Satellites) vs remote cache [1].

[1]: https://docs.earthly.dev/docs/caching#sharing-cache