code: public void taintPackagesDependingOnChangedPackages(Set<String> pkgs, Set<String> recentlyCompiled) {
          for (Package pkg : prev.packages().values()) {
              for (String dep : pkg.dependencies()) {
                  if (pkgs.contains(dep) && !recentlyCompiled.contains(pkg.name())) {
                      taintPackage(pkg.name(), " its depending on "+dep);
                  }
              }
          }
      }
docs: Propagate recompilation through the dependency chains.
  Avoid re-tainting packages that have already been compiled.