Seeing something strange when trying to implement my first plugin. The plugin seems to "work", in that I can use the target it creates in a BUILD file somewhere and it ends up correctly wiring through to existing pants goals (package, publish, and run). However, both the tests I have written alongside my plugin code and the mypy linter fail to run; they both complain about unowned imports in the test code. Does anybody have any suggestions?

❯ pants test ::
......
Engine traceback:
  in `test` goal
  in Run Pytest - pants/plugins/mypkg/something/else/foo_test.py:tests
  in Resolve transitive targets
  in Resolve direct dependencies of target - pants/plugins/mypkg/something/else/foo_test.py:tests
  in Inferring Python dependencies by analyzing source

UnownedDependencyError: Pants cannot infer owners for the following imports in the target pants/plugins/mypkg/something/else/foo_test.py:tests:

  * mypkg.something.else.foo.FooClass (line: 11)

If you do not expect an import to be inferrable, add `# pants: no-infer-dep` to the import line. Otherwise, see <https://www.pantsbuild.org/v2.15/docs/troubleshooting#import-errors-and-missing-dependencies> for common problems.

My code looks something like this:

# pants/plugins/mypkg/BUILD
pants_requirements(name="pants", resolve="pants-plugins")

# pants/plugins/mypkg/something/else/BUILD
python_sources(resolve="pants-plugins")
python_tests(name="tests", resolve="pants-plugins")

# pants/plugins/mypkg/something/else/foo.py
does something interesting

# pants/plugins/mypkg/something/else/foo_test.py
tests something interesting

# pants/plugins/mypkg/something/else/register.py
registers my plugin

# pants.toml
[GLOBAL]
pants_version = "2.15.0"
pythonpath = ["%(buildroot)s/pants/plugins"]

backend_packages.add = [
  ...
  "pants.backend.plugin_development",
  "mypkg.something.else", # my plugin gives me a new backend
]