Challenging to get started with workspaces.

[chrisfougner]

This is probably a me thing, but I haven't had luck getting workspaces to work, and I've had a pretty detailed read through the documentation.

This is what I have

root/
├── pyproject.toml
├── lib/
│   ├── pyproject.toml
│   ├── __init__.py
│   └── xyz.py  
└── tests/
    ├── pyproject.toml
    └── test.py

The files look like this:

root/pyproject.toml

[project]
...

[tool.uv.workspace]
members = ["lib", "tests"]

root/lib/pyproject.toml

[project]
name = "lib"
...

root/tests/pyproject.toml

[project]
...
dependencies = ["lib"]

[tool.uv.sources]
lib = {workspace = true}

root/tests/test.py

from lib import xyz 
...

And this is what I get:

$ uv run tests/test.py 
Traceback (most recent call last):
  File ".../root/tests/test.py", line 1, in <module>
    from lib import xyz
ImportError: cannot import name 'xyz' from 'lib' (unknown location)

[bluss]

The lib project there has a layout where __init__.py and pyproject.toml are on the same level. While any layout could work, that's definitely not a recommended or regular setup for a package project. uv init --lib can create a template that demonstrates an 'expected' layout. In this workspace it would look like either root/lib/lib/__init__.py or root/lib/src/lib/__init__.py together with root/lib/pyproject.toml for the lib part.

Maybe there's more to say but I thought it might help to bring up at least this lib thing in some detail, and that could get you going in the right direction. (Summary: before lib will work for you in the workspace, it needs to work as a standalone project.)

(If you see that and feel you don't want that layout - then maybe workspace is not what you want? Maybe root is just one project with lib and tests, doesn't need to be a workspace?)

[dylwil3]

I agree this is confusing!

I think you actually need both lib and tests to be packaged? At least, I wasn't able to get it to work without that. If that's true, probably this line of the documentation on workspaces should specify "packaged" application:

Every directory included by the members globs (and not excluded by the exclude globs) must contain a pyproject.toml file. However, workspace members can be either applications or libraries; both are supported in the workspace context.

Ideally the error message would help point the way a bit better here. In fact, the messages get more confusing if you make lib packaged but not tests - then I was getting a message telling me lib needed to be added as a workspace source... but it was!

Speaking of which, the line:

[tool.uv.sources]
lib = {workspace = true}

should probably go in root/pyproject.toml.

[chrisfougner]

Thanks for taking a look so quickly @bluss! I agree the structure isn't really ideal. Unfortunately I'm in the situation where there is an existing codebase I'm working with and want to keep refactors to a minimum.

I tried getting it to work with the path specifier as well: lib = {path = "../lib", editable = true}, but am getting the same error.

@dyllwil3: My understanding was that [tool.uv.sources] needs to be specified in each individual package. Is that not the case? Or is it only for workspace packages that they need to be specified at the root?

[bluss]

@chrisfougner is the lib project already working and building a wheel for itself correctly, in isolation? I want to underline this as a way to work with it.