packer: try to fix flaky test

packer/communicator.go

@@ -115,16 +115,16 @@ func (r *RemoteCmd) StartWithUi(c Communicator, ui Ui) error {
 	}
 
 	// Create the channels we'll use for data
-	exitCh := make(chan int, 1)
+	exitCh := make(chan struct{})
 	stdoutCh := iochan.DelimReader(stdout_r, '\n')
 	stderrCh := iochan.DelimReader(stderr_r, '\n')
 
 	// Start the goroutine to watch for the exit
 	go func() {
+		defer close(exitCh)
 		defer stdout_w.Close()
 		defer stderr_w.Close()
 		r.Wait()
-		exitCh <- r.ExitStatus
 	}()
 
 	// Loop and get all our output

packer/communicator_test.go

@@ -33,7 +33,7 @@ func TestRemoteCmd_StartWithUi(t *testing.T) {
 	rc.Wait()
 
 	expected := strings.TrimSpace(data)
-	if uiOutput.String() != expected+"\n" {
+	if strings.TrimSpace(uiOutput.String()) != expected {
 		t.Fatalf("bad output: '%s'", uiOutput.String())
 	}