allbuildtestrunquerystartup options
--python_version=<PY2 or PY3>
The Python major version mode, either `PY2` or `PY3`. Note that this is overridden by `py_binary` and `py_test` targets (even if they don't explicitly specify a version) so there is usually not much reason to supply this flag.
default: see description
loading and_analysis
affects outputs
explicit in_output_path