Which components of the system require rebuilding when making changes to module A, which depends on another module B that is not directly connected?

If module A depends on module B, but B is not directly connected to other modules, then when changes occur in module A, the following need to be rebuilt:

• The module A itself — changes in it require a rebuild.
• All modules that directly depend on module A, as their functionality may change due to changes in A.

Module B does not need to be rebuilt if there were no changes in it, as it does not depend on A and has not been modified.

In the context of Android, this means that when changes occur in module A:

• Module A is rebuilt.
• Modules that use A are rebuilt.
• Module B and its dependencies are not rebuilt unless they have changed.

This allows optimizing build time by avoiding unnecessary rebuilds of independent modules.