// DFS Recursive topological sort to load mods in order of dependencies.

  StringSet workingSet;
  StringSet visitedSet;
  StringList dependencySortedMods;

  function<void(String const&)> dependencySortVisit;
  dependencySortVisit = [&](String const& modName) {
      if (workingSet.contains(modName))
        throw StarException("Mod dependencies form a cycle");
      if (!visitedSet.contains(modName)) {
        workingSet.add(modName);
        for (auto const& depName : mods.get(modName).includes) {
          if (!mods.contains(depName))
            continue;
          dependencySortVisit(depName);
        }

        for (auto const& depName : mods.get(modName).requires) {
          if (!mods.contains(depName))
            throw StarException(strf("Mod '%s' is missing dependency '%s'", modName, depName));
          dependencySortVisit(depName);
        }

        workingSet.remove(modName);
        visitedSet.add(modName);
        dependencySortedMods.append(modName);
      }
    };

  for (auto const& modName : mods.keys())
    dependencySortVisit(modName);

  StringList dependencySortedPaths;
  for (auto const& modName : dependencySortedMods) {
    Logger::info("Detected mod '%s' at '%s'", modName, mods.get(modName).path);
    dependencySortedPaths.append(mods.get(modName).path);
  }
  return dependencySortedPaths;