fix format string issues as found by go vet

3 files changed, 5 insertions, 5 deletions

diff --git a/utils/merkletrie/difftree_test.go b/utils/merkletrie/difftree_test.go
index dd5b11d..9f033b1 100644
--- a/utils/merkletrie/difftree_test.go
+++ b/utils/merkletrie/difftree_test.go
@@ -120,7 +120,7 @@ func newChanges(original merkletrie.Changes) (changes, error) {
 				path:   c.From.String(),
 			}
 		default:
-			panic(fmt.Sprintf("unsupported action %d", c.Action))
+			panic(fmt.Sprintf("unsupported action %d", action))
 		}
 	}
 
diff --git a/utils/merkletrie/internal/fsnoder/new.go b/utils/merkletrie/internal/fsnoder/new.go
index 1e33020..ab749fd 100644
--- a/utils/merkletrie/internal/fsnoder/new.go
+++ b/utils/merkletrie/internal/fsnoder/new.go
@@ -34,7 +34,7 @@ func decodeDir(data []byte, isRoot bool) (*dir, error) {
 	var name string
 	switch end := bytes.IndexRune(data, dirStartMark); end {
 	case -1:
-		return nil, fmt.Errorf("%c not found")
+		return nil, fmt.Errorf("%c not found", dirStartMark)
 	case 0:
 		if isRoot {
 			name = ""
diff --git a/utils/merkletrie/iter_test.go b/utils/merkletrie/iter_test.go
index ba28f0b..7e8c302 100644
--- a/utils/merkletrie/iter_test.go
+++ b/utils/merkletrie/iter_test.go
@@ -65,7 +65,7 @@ func (t test) run(c *C, iter *merkletrie.Iter,
 
 	var obtained noder.Path
 	var err error
-	for i := range t.operations {
+	for i, b := range t.operations {
 		comment := Commentf("\ntree: %q\ntest #%d (%q)\noperation #%d (%q)",
 			treeDescription, testNumber, t.operations, i, t.operations[i])
 
@@ -81,8 +81,8 @@ func (t test) run(c *C, iter *merkletrie.Iter,
 				c.Assert(err, IsNil)
 			}
 		default:
-			c.Fatalf("unknown operation at test %d, operation %d (%s)\n",
-				testNumber, i, t.operations[i])
+			c.Fatalf("unknown operation at test %d, operation %d (%c)\n",
+				testNumber, i, b)
 		}
 		if i >= len(expectedChunks) {
 			c.Assert(err, Equals, io.EOF, comment)