Test logs error even if tree is nil

parser/test-common.go

@@ -9,6 +9,10 @@ func checkTree (modulePath string, correct string, test *testing.T) {
 	tree, err := Parse(modulePath)
 	if tree == nil {
 		test.Log("TREE IS NIL!")
+		if err != io.EOF && err != nil {
+			test.Log("returned error:")
+			test.Log(err)
+		}
 		test.Fail()
 		return
 	}