message: do not need to dereference an enum
diff: @@ -30,7 +30,7 @@ mod tests {
  let result = instance.call("stack-overflow", &[]);
  match result {
  - Err(err) => match *err {
  + Err(err) => match err {
  CallError::Runtime(RuntimeError::Unknown { msg }) => {
  assert!(!msg.contains("segmentation violation"));
  assert!(!msg.contains("bus error"));
  