code: public Map<String,Set<String>> getDependencies() {
          Map<String,Set<String>> new_deps = new HashMap<String,Set<String>>();
          if (explicitPackages == null) return new_deps;
          for (Name pkg : explicitPackages) {
              Set<Name> set = deps.get(pkg);
              if (set != null) {
                  Set<String> new_set = new_deps.get(pkg.toString());
                  if (new_set == null) {
                      new_set = new HashSet<String>();
                      // Modules beware....
                      new_deps.put(":"+pkg.toString(), new_set);
                  }
                  for (Name d : set) {
                      new_set.add(":"+d.toString());
                  }
              }
          }
          return new_deps;
      }
docs: Fetch the set of dependencies that are relevant to the compile
  that has just been performed. I.e. we are only interested in
  dependencies for classes that were explicitly compiled.
  @return