Nixos flake

[goodboy]

For those who want to hack on Nix(OS) using the most modern suggestion for an "impure overlay" from pyproject.nix and using uv,

https://pyproject-nix.github.io/pyproject.nix/templates.html#impure

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Try it

nix develop -c uv run pytest tests

i personally always use,

nix develop -c uv run xonsh to get my preferred user-shell for
hackin.

[Copilot]

Pull request overview

Adds a Nix flake-based dev shell aimed at “impure” uv-managed development, and updates Python dependency grouping/locking to support that workflow.

Changes:

• Introduce flake.nix/flake.lock to provide a nix develop dev shell.
• Restructure pyproject.toml dependency groups (split into devx, testing, repl, add lint).
• Regenerate uv.lock to reflect new groups and add ruff to the lock.

Reviewed changes

Copilot reviewed 2 out of 4 changed files in this pull request and generated 4 comments.

File	Description
flake.nix	Adds a Nix flake dev shell that installs Python/uv tooling and runs uv sync on shell entry.
flake.lock	Pins nixpkgs for the new flake-based workflow.
pyproject.toml	Refactors dependency groups and introduces a lint group for ruff.
uv.lock	Updates lock revision and records new dependency groups + locked ruff artifact set.

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[Copilot]

The flake’s description (and header comment) calls this an “impure overlay”, but this flake only defines devShells and does not provide an overlay output. Consider rewording to avoid misleading users (e.g., describe it as an impure dev shell).

Suggested change

	# An "impure" template thx to `pyproject.nix`,
	# https://pyproject-nix.github.io/pyproject.nix/templates.html#impure
	# https://github.com/pyproject-nix/pyproject.nix/blob/master/templates/impure/flake.nix
	{
	description = "An impure overlay using `uv` with Nix(OS)";
	# An "impure" dev shell template thanks to `pyproject.nix`,
	# https://pyproject-nix.github.io/pyproject.nix/templates.html#impure
	# https://github.com/pyproject-nix/pyproject.nix/blob/master/templates/impure/flake.nix
	{
	description = "An impure dev shell using `uv` with Nix(OS)";

[Copilot]

packages includes both ruff and pypkgs.ruff. These typically install the same ruff executable, which can lead to PATH ambiguity and unnecessary closure size. Pick one source (either the top-level pkgs.ruff or the Python package) and remove the other.

Suggested change

pypkgs.ruff

[Copilot]

cpython is defined as a single source of truth for the Python version, but packages still hard-codes python313. This makes it easy to accidentally desync the selected interpreter from cpython/venv_dir. Use the cpython variable consistently when selecting the Python derivation.

Suggested change

	packages = with pkgs; [
	# XXX, ensure sh completions activate!
	bashInteractive
	bash-completion
	# on nixos, use pkg(s)
	ruff
	pypkgs.ruff
	uv
	python313 # ?TODO^ how to set from `cpython` above?
	packages = [
	# XXX, ensure sh completions activate!
	pkgs.bashInteractive
	pkgs.bash-completion
	# on nixos, use pkg(s)
	pkgs.ruff
	pypkgs.ruff
	pkgs.uv
	pkgs.${cpython} # selected via `cpython`

[Copilot]

The shell hook runs uv sync --dev --all-extras --no-group lint, but lint is not included in the dev dependency-group in pyproject.toml, so --no-group lint is currently redundant. Dropping it avoids confusion and reduces the chance of failures if a user has an older uv that doesn’t recognize that flag.