feature_summary( [FILENAME <file>]
  [APPEND]
  [VAR <variable_name>]
  [INCLUDE_QUIET_PACKAGES]
  [FATAL_ON_MISSING_REQUIRED_PACKAGES]
  [DESCRIPTION "<description>" | DEFAULT_DESCRIPTION]
  [QUIET_ON_EMPTY]
  WHAT (ALL
  | PACKAGES_FOUND | PACKAGES_NOT_FOUND
  | <TYPE>_PACKAGES_FOUND | <TYPE>_PACKAGES_NOT_FOUND
  | ENABLED_FEATURES | DISABLED_FEATURES)
)