def _GetSkippedDetail(outcome):
  """Build a string with skippedDetail if present."""
  if outcome.skippedDetail:
    if outcome.skippedDetail.incompatibleDevice:
      return 'Incompatible device/OS combination'
    if outcome.skippedDetail.incompatibleArchitecture:
      return 'App does not support the device architecture'
    if outcome.skippedDetail.incompatibleAppVersion:
      return 'App does not support the OS version'
  return 'Unknown reason'