Is possible an option to cache also build of own code?

[jhg]

The idea is an option default to false to improve builds as Rust compiler will have cache and only need to build the changes.

[Swatinem]

The idea is that the tradeoff to only cache dependencies is better because:

• it would only cache the first invocation when it generates a new cache key.
• with time the code will diverge more, causing longer builds.
• incremental needs a lot of disk space, and thus cache space and time to fetch & extract, lowering the benefits.

[jhg]

Thanks for the comment @Swatinem. About the first two points, I was thinking in incremental and default to false, but I guess that could be complex to do. And interesting the third point.