I believe this is tied to my plugin, but it's not very obvious how. Any ideas?

16:33:47.09 [ERROR] 1 Exception encountered:

Engine traceback:
  in select
  in pants.core.goals.test.run_tests
  in pants.core.goals.test.enrich_test_result (a/b/c/test_c.py:tests)
  in pants.backend.python.goals.pytest_runner.run_python_test (a/b/c/test_c.py:tests)
  in pants.backend.python.goals.pytest_runner.setup_pytest_for_target
  in pants.backend.python.util_rules.python_sources.prepare_python_sources
  in pants.core.util_rules.source_files.determine_source_files
Traceback (most recent call last):
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/engine/internals/native.py", line 69, in generator_send
    res = func.send(arg)
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/core/util_rules/source_files.py", line 74, in determine_source_files
    hydrated_sources.snapshot.digest for hydrated_sources in all_hydrated_sources
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/core/util_rules/source_files.py", line 74, in <genexpr>
    hydrated_sources.snapshot.digest for hydrated_sources in all_hydrated_sources
AttributeError: 'Digest' object has no attribute 'digest'
Traceback (most recent call last):
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/bin/local_pants_runner.py", line 281, in run
    engine_result = self._run_v2()
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/bin/local_pants_runner.py", line 193, in _run_v2
    return self._maybe_run_v2_body(goals, poll=False)
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/bin/local_pants_runner.py", line 215, in _maybe_run_v2_body
    poll_delay=(0.1 if poll else None),
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/init/engine_initializer.py", line 126, in run_goal_rules
    goal_product, params, poll=poll, poll_delay=poll_delay
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/engine/internals/scheduler.py", line 570, in run_goal_rule
    self._raise_on_error([t for _, t in throws])
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/engine/internals/scheduler.py", line 534, in _raise_on_error
    wrapped_exceptions=tuple(t.exc for t in throws),
pants.engine.internals.scheduler.ExecutionError: 1 Exception encountered:

Engine traceback:
  in select
  in pants.core.goals.test.run_tests
  in pants.core.goals.test.enrich_test_result (a/b/c/test_c.py:tests)
  in pants.backend.python.goals.pytest_runner.run_python_test (a/b/c/test_c.py:tests)
  in pants.backend.python.goals.pytest_runner.setup_pytest_for_target
  in pants.backend.python.util_rules.python_sources.prepare_python_sources
  in pants.core.util_rules.source_files.determine_source_files
Traceback (most recent call last):
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/engine/internals/native.py", line 69, in generator_send
    res = func.send(arg)
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/core/util_rules/source_files.py", line 74, in determine_source_files
    hydrated_sources.snapshot.digest for hydrated_sources in all_hydrated_sources
  File "/home/noah/.cache/pants/setup/bootstrap-Linux-x86_64/2.0.0b3_py36/lib/python3.6/site-packages/pants/core/util_rules/source_files.py", line 74, in <genexpr>
    hydrated_sources.snapshot.digest for hydrated_sources in all_hydrated_sources
AttributeError: 'Digest' object has no attribute 'digest'

One of the objects that’s having

.digest

called on it is already a

Digest

object, whereas the code probably assumes it’s a

Snapshot

. If you can update your gist, I can take a look if anything looks fishy. (MyPy is also helpful for this, although I don’t think that MyPy is yet “taught” how to use Pants’s type hints when you’re using Pants as a third-party library. We need to do PEP 561)

Oh, I see, the stacktrace is running tests. It’s not erroring in your codegen rule. `GeneratedSources`’s constructor takes a

Snapshot

, rather than

Digest

. That’s where it’s breaking. Rather than

await Get(Digest, AddPrefix)

, use

await Get(Snapshot, AddPrefix)

. The engine will “enrich” the digest into a snapshot

Oh got it