Good point! It is easy to add missing dependencies, but there is no tooling to spot and remove unnecessary dependencies (and not just in Go but all of Debian).
I occasionally read the go.mod diff on upstream important to see what changed, but it is all manual. It would be cool if the dh-golang had some built-in ptrace based thing that could say something like "Warning: the package has dependency X defined but no files from the package were accessed during the build. The dependency can most likely be removed."
