    # File lib/phusion_passenger/platform_info/ruby.rb, line 48
            def self.ruby_command
                    if in_rvm?
                            name = rvm_ruby_string
                            dir = rvm_path
                            if name && dir
                                    filename = "#{dir}/wrappers/#{name}/ruby"
                                    if File.exist?(filename)
                                            contents = File.open(filename, 'rb') do |f|
                                                    f.read
                                            end
                                            # Old wrapper scripts reference $HOME which causes
                                            # things to blow up when run by a different user.
                                            if contents.include?("$HOME")
                                                    filename = nil
                                            end
                                    else
                                            filename = nil
                                    end
                                    if filename
                                            return filename
                                    else
                                            STDERR.puts "Your RVM wrapper scripts are too old. Please " +
                                                    "update them first by running 'rvm get head && " +
                                                    "rvm reload && rvm repair all'."
                                            exit 1
                                    end
                            else
                                    # Something's wrong with the user's RVM installation.
                                    # Raise an error so that the user knows this instead of
                                    # having things fail randomly later on.
                                    # 'name' is guaranteed to be non-nil because rvm_ruby_string
                                    # already raises an exception on error.
                                    STDERR.puts "Your RVM installation appears to be broken: the RVM " +
                                            "path cannot be found. Please fix your RVM installation " +
                                            "or contact the RVM developers for support."
                                    exit 1
                            end
                    else
                            return ruby_executable
                    end
            end