message: Return test error code to user.
diff: @@ -31,6 +31,7 @@ mod ptrace_control;
  pub fn trace(configs: &[Config]) -> Result<TraceMap, RunError> {
  let mut tracemap = TraceMap::new();
  let mut tarpaulin_result = Ok(());
  + let mut ret = 0i32;
  for config in configs.iter() {
  if config.name == "report" {
  @@ -45,9 +46,7 @@ pub fn trace(configs: &[Config]) -> Result<TraceMap, RunError> {
  }
  match launch_tarpaulin(config) {
  Ok((t, r)) => {
  - if r != 0 {
  - warn!("Test exit code: {}", r);
  - }
  + ret |= r;
  tracemap.merge(&t);
  }
  Err(e) => {
  @@ -57,7 +56,12 @@ pub fn trace(configs: &[Config]) -> Result<TraceMap, RunError> {
  }
  }
  tracemap.dedup();
  +
  + if ret == 0 {
  tarpaulin_result.map(|_| tracemap)
  + } else {
  + Err(RunError::TestFailed)
  + }
  }
  pub fn run(configs: &[Config]) -> Result<(), RunError> {
  