add_custom_target(format-diff
  #COMMAND python ${CMAKE_SOURCE_DIR}/dist/format.py)
  COMMAND python2 ${CMAKE_SOURCE_DIR}/dist/format.py)
add_custom_target(format
  #COMMAND python ${CMAKE_SOURCE_DIR}/dist/format.py -i)
  COMMAND python2 ${CMAKE_SOURCE_DIR}/dist/format.py -i)