[bug] Python toolchain does not detect workspace dependencies with PEP 508 extras, version specifiers, or markers

[bilelomrani1]

Describe the bug

The Python toolchain detects workspace dependencies by matching [project.dependencies] names against other workspace projects. However, it only matches bare names, dependencies with any PEP 508 qualifier (extras, version specifiers, markers) are silently skipped.

In practice, workspace dependencies in pyproject.toml sometimes include at least one qualifier, here is an example in a uv workspace:

# packages/my-app/pyproject.toml
[project]
dependencies = ["my-lib[server]"]

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

Here my-lib is unambiguously a workspace dep via [tool.uv.sources], but Moon skips it because of the [server] extra. The workaround is to declare dependsOn manually in moon.yml.

Steps to reproduce

1. Create a uv workspace with two packages:

my-workspace/
├── pyproject.toml          
├── packages/
│   ├── my-lib/
│   │   ├── pyproject.toml  
│   │   └── moon.yml
│   └── my-app/
│       ├── pyproject.toml  
│       └── moon.yml

2. In packages/my-app/pyproject.toml:

[project]
name = "my-app"
dependencies = ["my-lib[server]"]

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

3. Run moon project my-app — the "Depends on" section does not list my-lib.

4. Change the dependency to bare my-lib (no extras); now it's detected.

Expected behavior

my-app should list my-lib as a dependency. Extras, version specifiers, and environment markers are PEP 508 qualifiers on the requirement, they don't change the identity of the package.

Ideally, all of the following (and combinations) should resolve to a dependency on the my-lib workspace project:

Dependency string	PEP 508 component
my-lib	Bare name
my-lib[server]	Extras
my-lib>=1.0	Version specifier
my-lib; python_version >= "3.12"	Environment marker

---

I'm open to contributing a fix, @milesj feel free to assign this to me if you want me to give it a shot.

[milesj]

We actually parse the requirement and then match it on name: https://github.com/moonrepo/plugins/blob/master/toolchains/python/src/tier2.rs#L55

https://docs.rs/pep508_rs/latest/pep508_rs/struct.Requirement.html#structfield.name

Something else must be going on.

[milesj]

@bilelomrani1 Do you have an example repo I can try and reproduce with.

[bilelomrani1]

Here's a minimal repro: https://github.com/bilelomrani1/moon-extras-repro

git clone https://github.com/bilelomrani1/moon-extras-repro
cd moon-extras-repro
moon project my-app

Changing the dep from my-lib[server] to bare my-lib in packages/my-app/pyproject.toml makes it detected.