# File src/ruby_supportlib/phusion_passenger/platform_info/ruby.rb, line 222
    def self.rvm_paths
      if in_rvm?
        result = []
        [ENV['rvm_path'], "#{PhusionPassenger.home_dir}/.rvm", "/usr/local/rvm"].each do |path|
          next if path.nil?
          rubies_path = File.join(path, 'rubies')
          wrappers_path = File.join(path, 'wrappers')
          gems_path = File.join(path, 'gems')
          if File.directory?(path) && (File.directory?(rubies_path) ||
             File.directory?(wrappers_path) || File.directory?(gems_path))
            result << path
          end
        end
        if result.empty?
          # Failure to locate the RVM path is probably caused by the
          # user customizing $rvm_path. Older RVM versions don't
          # export $rvm_path, making us unable to detect its value.
          STDERR.puts "Unable to locate the RVM path. Your RVM installation " +
            "is probably too old. Please update it with " +
            "'rvm get head && rvm reload && rvm repair all'."
          exit 1
        else
          return result
        end
      else
        return nil
      end
    end