I’m trying to package a

python_distribution

that depends on some

protobuf_sources

in a sibling directory. What do I need to specify in my dependencies field in order to satisfy the ownership constraint? Right now I have the following:

python_sources(name="lib")

python_distribution(
    name="auth_service_client",
    dependencies=[
        ":lib",
        "src/proto/auth_service/service.proto:auth_service_interfaces",
    ],
    provides=python_artifact(
        name="auth_service_client",
        version="0.0.1",
    ),
)

This is in the subdirectory that has my python sources for the library. It depends on some codegen protocol buffers in a sibling directory with the following BUILD file:

protobuf_sources(
    name="auth_service_interfaces",
    python_source_root="src/python",
    grpc=True,    
)

Pants is aware of the dependency between the

python_source

generated by `python_sources`:

./pants dependencies src/python/auth_service_client/client.py
src/proto/auth_service/service.proto:auth_service_interfaces
src/python:reqs#grpcio

But when I try to package, I get the following error message:

NoOwnerError: No python_distribution target found to own src/proto/auth_service/service.proto:auth_service_interfaces. Note that the owner must be in or above the owned target's directory, and must depend on it (directly or indirectly). See <https://www.pantsbuild.org/v2.14/docs/python-distributions> for how python_sources targets are mapped to distributions. See <https://www.pantsbuild.org/v2.14/docs/python-distributions>.

I read through the docs but I’m not understanding how to map the

protobuf_sources

to a

python_sources

target that my distribution can depend on. What am I missing here?

"Note that the owner must be in or above the owned target's directory" - that's the missing bit. You have sibling directories. There is a bit of a long explanation about why this constraint exists, but that's somewhat immaterial and I'll stop there for now.

Got it. So if my tree looks like this:

.
├── pants
├── pants.toml
└── src
    ├── go
    │   ├── BUILD
    │   ├── cmd
    │   │   └── auth-server
    │   │       ├── BUILD
    │   │       └── main.go
    │   ├── go.mod
    │   ├── go.sum
    │   └── pkg
    ├── proto
    │   └── auth_service
    │       ├── BUILD
    │       └── service.proto
    └── python
        ├── BUILD
        ├── auth_service_client
        │   ├── BUILD
        │   ├── __init__.py
        │   └── client.py
        ├── auth_test_service
        │   ├── BUILD
        │   ├── __init__.py
        │   └── main.py
        ├── requirements.lock
        └── requirements.txt

The only way to package

auth_service_client

is by creating a BUILD file in

src

or the root of the repo?

The history is Twitter and bad practices in JVM land. Basically trying to prevent the same source getting published in >1 public artifact ever.

In a nutshell: for each python source, Pants needs to choose a single

python_distribution

to publish it in. There is a documented algorithm for how it selects that

python_distribution

, and that algorithm relies on it being "above" the source file in the filesystem hierarchy.

That makes sense, thanks guys. Just not obvious how that applies to codegen’d code. Copy/pasting my

python_distribution

into a new BUILD file in the parent src directory and then adjusting the path to

:lib

worked exactly as expected.