capture (Capistrano::Configuration::Actions::Inspect)

    # File lib/capistrano/configuration/actions/inspect.rb, line 32
            def capture(command, options={})
              output = ""
              invoke_command(command, options.merge(:once => true)) do |ch, stream, data|
                case stream
                when :out then output << data
                when :err then warn "[err :: #{ch[:server]}] #{data}"
                end
              end
              output
            end