@@ -377,7 +377,7 @@ func (b *Builder) processImageFrom(img *imagepkg.Image) error {

 	// FIXME rewrite this so that builder/parser is used; right now steps in

 	// onbuild are muted because we have no good way to represent the step

 	// number

-	for _, step := range onBuildTriggers {

+	for stepN, step := range onBuildTriggers {

 		splitStep := strings.Split(step, " ")

 		stepInstruction := strings.ToUpper(strings.Trim(splitStep[0], " "))

 		switch stepInstruction {

@@ -392,6 +392,7 @@ func (b *Builder) processImageFrom(img *imagepkg.Image) error {

 		// longer be necessary.

 		if f, ok := evaluateTable[strings.ToLower(stepInstruction)]; ok {

+			fmt.Fprintf(b.OutStream, "Trigger %d, %s\n", stepN, step)

 			if err := f(b, splitStep[1:], nil); err != nil {

 				return err

 			}

@@ -2142,3 +2142,25 @@ func TestBuildEmptyCmd(t *testing.T) {

 	}

 	logDone("build - empty cmd")

 }

+

+func TestBuildOnBuildOutput(t *testing.T) {

+	name := "testbuildonbuildparent"

+	defer deleteImages(name)

+	if _, err := buildImage(name, "FROM busybox\nONBUILD RUN echo foo\n", true); err != nil {

+		t.Fatal(err)

+	}

+

+	childname := "testbuildonbuildchild"

+	defer deleteImages(childname)

+

+	_, out, err := buildImageWithOut(name, "FROM "+name+"\nMAINTAINER quux\n", true)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if !strings.Contains(out, "Trigger 0, run echo foo") {

+		t.Fatal("failed to find the ONBUILD output")

+	}

+

+	logDone("build - onbuild output")

+}