class Bundler::ParallelInstaller

def check_for_unmet_dependencies
  unmet_dependencies = @specs.map do |s|
    [
      s,
      s.dependencies.reject {|dep| @specs.any? {|spec| dep.matches_spec?(spec.spec) } },
    ]
  end.reject {|a| a.last.empty? }
  return if unmet_dependencies.empty?
  warning = []
  warning << "Your lockfile doesn't include a valid resolution."
  warning << "You can fix this by regenerating your lockfile or manually editing the bad locked gems to a version that satisfies all dependencies."
  warning << "The unmet dependencies are:"
  unmet_dependencies.each do |spec, unmet_spec_dependencies|
    unmet_spec_dependencies.each do |unmet_spec_dependency|
      found = @specs.find {|s| s.name == unmet_spec_dependency.name && !unmet_spec_dependency.matches_spec?(s.spec) }
      if found
        warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name}, unsatisfied by #{found.full_name}"
      else
        warning << "* #{unmet_spec_dependency}, dependency of #{spec.full_name} but missing from lockfile"
      end
    end
  end
  Bundler.ui.warn(warning.join("\n"))
end