def missing_dependencies
      missing = []
      dependency_versions(:recursive => false).each do |pkg, target_versions|
        found = false
        target_versions.each do |_target, versions|
          dependency = dependency_for(pkg)
          found = versions.any? { |version| dependency.match?(pkg, version) }
        end
        missing << pkg unless found
      end
      missing
    end
def missing_dependencies
      missing = []
      dependency_versions(:recursive => false).each do |pkg, target_versions|
        found = false
        target_versions.each do |_target, versions|
          dependency = dependency_for(pkg)
          found = versions.any? { |version| dependency.match?(pkg, version) }
        end
        missing << pkg unless found
      end
      missing
    end
Return missing dependencies