message: Fixed result merging.
  I'd missed out the deduplication step having moved it down into run_tests
diff: @@ -96,6 +96,7 @@ pub fn launch_tarpaulin(config: &Config) -> Result<(TraceMap, i32), RunError> {
  result.merge(&run_result.0);
  return_code |= run_result.1;
  }
  + result.dedup();
  Ok((result, return_code))
  }
  @@ -132,6 +133,7 @@ fn run_tests(workspace: &Workspace, compile_options: CompileOptions, config: &Co
  fn run_doctests(workspace: &Workspace,
  compile_options: CompileOptions,
  config: &Config) -> Result<(TraceMap, i32), RunError> {
  + info!("Running doctests");
  let mut result = TraceMap::new();
  let mut return_code = 0i32;
  @@ -149,7 +151,6 @@ fn run_doctests(workspace: &Workspace,
  };
  let walker = WalkDir::new(&doctest_dir).into_iter();
  for dt in walker.filter_map(|e| e.ok()).filter(|e| e.file_type().is_file()) {
  - trace!("Processing {}", config.strip_project_path(dt.path()).display());
  if let Some(res) = get_test_coverage(&workspace, None, dt.path(), config, false)?
  {
  result.merge(&res.0);
  @@ -157,6 +158,7 @@ fn run_doctests(workspace: &Workspace,
  }
  }
  + result.dedup();
  Ok((result, return_code))
  }
  @@ -196,10 +198,9 @@ fn get_compile_options<'a>(config: &Config,
  }
  fn setup_environment(config: &Config) {
  + let common_opts = " -C relocation-model=dynamic-no-pic -C link-dead-code -C opt-level=0 -C debuginfo=2 ";
  let rustflags = "RUSTFLAGS";
  - let mut value =
  - " -C relocation-model=dynamic-no-pic -C link-dead-code -C opt-level=0 -C debuginfo=2 "
  - .to_string();
  + let mut value = common_opts.to_string();
  if config.release {
  value = format!("{}-C debug-assertions=off ", value);
  }
  @@ -209,7 +210,7 @@ fn setup_environment(config: &Config) {
  env::set_var(rustflags, value);
  // doesn't matter if we don't use it
  let rustdoc = "RUSTDOCFLAGS";
  - let mut value = format!("--persist-doctests {} -Z unstable-options ", DOCTEST_FOLDER);
  + let mut value = format!("{} --persist-doctests {} -Z unstable-options ", common_opts, DOCTEST_FOLDER);
  if let Ok(vtemp) = env::var(rustdoc) {
  value.push_str(vtemp.as_ref());
  }
  