Python 3 - resources_task creating unexpected targets after reset

[Eric-Arellano]

Problem

Both of the test_incremental() tests are failing in test_resources_task.py.

==================== FAILURES ====================
                     _ MinimalImplResourcesTaskTest.test_incremental __

                     self = <pants_test.backend.jvm.tasks.test_resources_task.MinimalImplResourcesTaskTest testMethod=test_incremental>

                         def test_incremental(self):
                           task = self.create_resources_task(target_roots=[self.create_target('a:1'),
                                                                           self.create_target('b:1')])
                           processed_targets = task.execute()

                           self.assertEqual(sorted([self.target('a:1'), self.target('b:1')]), sorted(processed_targets))
                           self.assert_products(task, self.target('a:1'), 1)
                           self.assert_products(task, self.target('b:1'), 1)

                           # Test incremental works - no changes.
                           self.reset_build_graph()
                           task = self.create_resources_task(target_roots=[self.create_target('a:1'),
                                                                           self.create_target('b:1')])
                           processed_targets = task.execute()

                     >     self.assertEqual([], processed_targets)
                     E     AssertionError: Lists differ: [] != [TestTarget(a:1), TestTarget(b:1)]
                     E
                     E     Second list contains 2 additional elements.
                     E     First extra element 0:
                     E     TestTarget(a:1)
                     E
                     E     - []
                     E     + [TestTarget(a:1), TestTarget(b:1)]

                     .pants.d/pyprep/sources/0149f6d60c1f81255ffbf3cd4ca6bef56274a538/pants_test/backend/jvm/tasks/test_resources_task.py:136: AssertionError

To reproduce

1. ./pants clean-all
2. ./pants --python-setup-interpreter-constraints='["CPython>=3.5"]' test tests/python/pants_test/backend/jvm/tasks:test_resources_task.py

My confusion

I don't understand why process_targets is supposed to be empty in the last line, after calling task.execute().

  def test_incremental(self):
    task = self.create_resources_task(target_roots=[self.create_target('a:1'),
                                                    self.create_target('b:1')])
    processed_targets = task.execute()

    self.assertEqual(sorted([self.target('a:1'), self.target('b:1')]), sorted(processed_targets))
    self.assert_products(task, self.target('a:1'), 1)
    self.assert_products(task, self.target('b:1'), 1)

    # Test incremental works - no changes.
    self.reset_build_graph()
    task = self.create_resources_task(target_roots=[self.create_target('a:1'),
                                                    self.create_target('b:1')])
    processed_targets = task.execute()

    self.assertEqual([], processed_targets)

[jsirois]

This is a b'' != '' under python3 bug in the CacheManager code graph. Fix forthcoming.

[jsirois]

Fix lumped into #6379 with 053fb46.