Summary

Our monorepo follows the standard pattern of being split into deployed /apps and bundled /packages. All of the /packages have a build script that produces a /dist output, which are being cached during CI. When those packages are built we mark all dependencies in that package's package.json as externals so they are not bundled in the final output. This way the /dist output for each package is small - essentially just the bundled source - and the /apps have the ultimate responsibility of combining everything, including dependencies, into the final JS bundle.

The problem is when packages depend on each other the dependencies are part of calculation for determining what is cached, even if the output from the task doesn't change. For example, we might have a dependency chain where package A depends on package B, and B depends on package C. If we make a change to the /src of package C we want the a new version of the output to be cached. However, even though C is marked as an external for B (and B as external for A), both A and B end up rebuilding, even though the final output contents remain unchanged.

Is there a way to tell the build script to only depend on changes to the immediate package's /src and nothing else?

Additional information

I've tried setting the build task in the root turbo.json as:

"build": {
	"dependsOn": ["^build"],
	"inputs": ["src/**"],
	"outputs": ["dist/**"],
},

However, if I make a change to a dependency down the line it will still rebuild all of the packages up the dependency stream.

Example

No response