Please add -v option for verbose output with usage (which class and where it was used)

[plokhotnyuk]

Some time it is not clear were in your project unwanted usage is happening and clear pointing to source code line with class name that is used would helped a lot.

[cb372]

Nice idea!

The plugin relies on zinc to decide which libraries your project depends on for compilation. It looks like zinc provides a useful function that we might be able to use for this:

  /** The library dependencies for the source file `src`. */
  def libraryDeps(src: File): Set[File]

So we could iterate through the project's source files and call that function for each one.