diff --git a/cgroups/fs/utils_test.go b/cgroups/fs/utils_test.go
index 4dd2243e..63d743f0 100644
--- a/cgroups/fs/utils_test.go
+++ b/cgroups/fs/utils_test.go
@@ -31,7 +31,7 @@ func TestGetCgroupParamsInt(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	} else if value != floatValue {
-		t.Fatalf("Expected %f to equal %f", value, floatValue)
+		t.Fatalf("Expected %d to equal %f", value, floatValue)
 	}
 
 	// Success with new line.
@@ -43,7 +43,7 @@ func TestGetCgroupParamsInt(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	} else if value != floatValue {
-		t.Fatalf("Expected %f to equal %f", value, floatValue)
+		t.Fatalf("Expected %d to equal %f", value, floatValue)
 	}
 
 	// Not a float.
diff --git a/mount/pivotroot.go b/mount/pivotroot.go
index 447f5904..ffd60513 100644
--- a/mount/pivotroot.go
+++ b/mount/pivotroot.go
@@ -4,17 +4,18 @@ package mount
 
 import (
 	"fmt"
-	"github.com/dotcloud/docker/pkg/system"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"syscall"
+
+	"github.com/dotcloud/docker/pkg/system"
 )
 
 func PivotRoot(rootfs string) error {
 	pivotDir, err := ioutil.TempDir(rootfs, ".pivot_root")
 	if err != nil {
-		return fmt.Errorf("can't create pivot_root dir %s", pivotDir, err)
+		return fmt.Errorf("can't create pivot_root dir %s, error %v", pivotDir, err)
 	}
 	if err := system.Pivotroot(rootfs, pivotDir); err != nil {
 		return fmt.Errorf("pivot_root %s", err)