Peculiar problem. I have a working codebase, including some tests that use pytest-asyncio. The codebase had a single resolve for all python deps. I am now breaking it into separate resolves. I have introduced a new resolve "edge" that includes a bunch of things, including the tests that use pytest-asyncio. locally I can run the tests. in CI, I receive an error

async def functions are not natively supported.
You need to install a suitable plugin for your async framework, for example:
  - anyio
  - pytest-asyncio
  - pytest-tornasync
  - pytest-trio
  - pytest-twisted

Which implies that pytest-asyncio is not installed. pytest-asyncio is in the lockfile for both "edge" and the "pytest" resolve. I'm unsure where to go with this, or where to poke at it to try and reproduce.

What is in your

pants.toml

?

[pytest]
install_from_resolve = "universal_resolve"
requirements = [
    "//3rdparty/python:poetry#pytest",
    "//3rdparty/python:poetry#pytest-asyncio",
]

I have this in my pants.toml. You might need something similar to enforce that pants knows to pick up the plugin dependency

pytest infers its plugins by searching your file system, so if you run in a sandbox as pants does, you need to explicitly set the dependency. In other words, pants can't tell that your tests need this plugin because there are no import statements or metadata in pytest itself that reference pytest-asyncio. So you have to be explicit about it

Sure.

[pytest]
install_from_resolve = "pytest"
execution_slot_var = "PANTS_EXECUTION_SLOT"
args = [
  # This means we don't need to add the @pytest.mark.asyncio decorator above
  # async tests.
  "--asyncio-mode=auto",
]

# Include plugins and things that should be ambiently available here.
requirements = [
 "//3rdparty/python:pytest",
]

I'm a little confused by the interaction between pants.toml and pants.ci.toml here - from memory, the ci toml is merged with the base configuration, overriding things that are specified for ci?