def METHOD_NAME(root_dir=None):
  """Runs `gn gen --check` with default args to detect mismatches between
  #includes and dependencies in the BUILD.gn files, as well as general build
  errors.
  Returns a list of error summary strings.
  """
  out_dir = tempfile.mkdtemp('gn')
  try:
    error = RunGnCommand(['gen', '--check', out_dir], root_dir)
  finally:
    shutil.rmtree(out_dir, ignore_errors=True)
  return GN_ERROR_RE.findall(error) if error else []