Bug fix. Variant names with dashes (e.g. `with-chardet`, `django-5`, `pkg-23`) were being truncated by `test-cell-py%`'s stem parser — it used `cut -d- -f2` (single field) instead of `-f2-` (from field 2 to end).
Present since v0.1.0; surfaced validating `feedparser` with `DEP_MODE := group` where `with-chardet` / `without-chardet` are the natural variant names.
The `examples/with-matrix/` example now uses `pkg-23` / `pkg-24` so the CI smoke test regression-guards the fix.
Install
```bash
curl -sSL https://raw.githubusercontent.com/python-developer-tooling-handbook/makefile.uv/v0.2.1/Makefile.uv -o Makefile.uv
```