E           pants.engine.internals.scheduler.ExecutionError: 1 Exception encountered:
E           
E           Engine traceback:
E             in select
E             in pants.backend.codegen.protobuf.python.rules.generate_python_from_protobuf ({self.protocol_target.address.spec})
E             in pants.engine.process.fallible_to_exec_result_or_raise
E           Traceback (most recent call last):
E             File "/tmp/process-executionNwaCfx/src/python/pants/engine/process.py", line 262, in fallible_to_exec_result_or_raise
E               description.value,
E           pants.engine.process.ProcessExecutionFailure: Process 'Generating Python sources from src/protobuf/dir1.' failed with exit code 1.
E           stdout:
E           
E           stderr:
E           Traceback (most recent call last):
E             File "/tmp/process-executionkoj6j8/.cache/pex_root/venvs/7a60680810e39003bff7735055fba9f05cad6eb0/44bf65ec4b573a3d710ed08dd3dbbf662b72808e/bin/protoc-gen-mypy", line 5, in <module>
E               from mypy_protobuf import main
E             File "/home/runner/.cache/pants/named_caches/pex_root/venvs/short/236b4726/lib/python3.6/site-packages/mypy_protobuf.py", line 11, in <module>
E               import six
E           ModuleNotFoundError: No module named 'six'
E           --mypy_out: protoc-gen-mypy: Plugin failed with status code 1.

src/python/pants/engine/internals/scheduler.py:508: ExecutionError
=============================== warnings summary ===============================
src/python/pants/backend/codegen/protobuf/python/rules_integration_test.py:234