namespaced packages ignored/mis-named

[H-Plus-Time]

Bug Description

PEP 420-style namespace packages like the following:

foo_a/
  Cargo.toml
  python/foo/a/
    __init__.py
  pyproject.toml
  src/
    lib.rs
foo_b/
  Cargo.toml
  python/foo/b/
    __init__.py
  pyproject.toml
  src/
    lib.rs

are skipped entirely in find_spec (because they appear as if they are not top-level packages, since importlib.util.find_spec passes a specialized _NamespacePath to find_spec).

Flagging on enable_automatic_installation appears to work, but actually just installs the namespaced package as foo (resulting in silent clobbering of members of the namespace).

I should have a PR soon-ish for this.

Steps to Reproduce

1. Initialize a boilerplate folder structure along the lines described above, marking python-source = "python", module-name = "foo.._rustin the Cargo.tomls and insertingfrom . import _rust`.
2. install the hook and import from a venv with the namespace members editable-installed.
3. Modify any of the files - observe the hook missing them.

Please provide the output of python -m maturin_import_hook version (or provide manually)

OS: Linux-6.12.4-arch1-1-x86_64-with-glibc2.40
Python: CPython 3.12.8
maturin-import-hook: 0.2.0
maturin: maturin 1.7.8
rustc: rustc 1.81.0 (eeb90cda1 2024-09-04)
pip: ?

Does maturin develop work when run manually for your project?

• Yes/No (leave blank if not applicable)

[H-Plus-Time]

A few repositories where this happens:

• https://github.com/kylebarron/arro3
• https://github.com/geoarrow/geoarrow-rs/tree/main/python

Quite possible this is only in mixed python/rust projects, and reproducible in both src-layout and flat-layout packages.

[kylebarron]

I also just hit this 😅

Looks like #18 should fix this.

[H-Plus-Time]

@kylebarron there's still a number of test failures (by the looks of it, I've winnowed it down to differences in expected package names in the tests), but it should be fairly usable on namespaced packages if you want to take it for a spin in the meantime.