Nixos flake

flake.nix

@@ -0,0 +1,70 @@
+# 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 (w dev-shell) using `uv`";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs =
+    { nixpkgs, ... }:
+    let
+      inherit (nixpkgs) lib;
+      forAllSystems = lib.genAttrs lib.systems.flakeExposed;
+    in
+    {
+      devShells = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+
+          # XXX NOTE XXX, for now we overlay specific pkgs via
+          # a major-version-pinned-`cpython`
+          cpython = "python313";
+          venv_dir = "py313";
+          pypkgs = pkgs."${cpython}Packages";
+        in
+        {
+          default = pkgs.mkShell {
+
+            packages = [
+              # XXX, ensure sh completions activate!
+              pkgs.bashInteractive
+              pkgs.bash-completion
+
+              # XXX, on nix(os), use pkgs version to avoid
+              # build/sys-sh-integration issues
+              pkgs.ruff
+
+              pkgs.uv
+              pkgs.${cpython}# ?TODO^ how to set from `cpython` above?
+            ];
+
+            shellHook = ''
+              # unmask to debug **this** dev-shell-hook
+              # set -e
+
+              # link-in c++ stdlib for various AOT-ext-pkgs (numpy, etc.)
+              LD_LIBRARY_PATH="${pkgs.stdenv.cc.cc.lib}/lib:$LD_LIBRARY_PATH"
+
+              export LD_LIBRARY_PATH
+
+              # RUNTIME-SETTINGS
+              # ------ uv ------
+              # - always use the ./py313/ venv-subdir
+              # - sync env with all extras
+              export UV_PROJECT_ENVIRONMENT=${venv_dir}
+              uv sync --dev --all-extras
+
+              # ------ TIPS ------
+              # NOTE, to launch the py-venv installed `xonsh` (like @goodboy)
+              # run the `nix develop` cmd with,
+              # >> nix develop -c uv run xonsh
+            '';
+          };
+        }
+      );
+    };
+}

pyproject.toml

@@ -53,22 +53,33 @@ dependencies = [
 
 [dependency-groups]
 dev = [
-  # test suite
-  # TODO: maybe some of these layout choices?
-  # https://docs.pytest.org/en/8.0.x/explanation/goodpractices.html#choosing-a-test-layout-import-rules
-  "pytest>=8.3.5",
-  "pexpect>=4.9.0,<5",
+  {include-group = 'devx'},
+  {include-group = 'testing'},
+  {include-group = 'repl'},
+]
+devx = [
   # `tractor.devx` tooling
   "greenback>=1.2.1,<2",
   "stackscope>=0.2.2,<0.3",
   # ^ requires this?
   "typing-extensions>=4.14.1",
-
+]
+testing = [
+  # test suite
+  # TODO: maybe some of these layout choices?
+  # https://docs.pytest.org/en/8.0.x/explanation/goodpractices.html#choosing-a-test-layout-import-rules
+  "pytest>=8.3.5",
+  "pexpect>=4.9.0,<5",
+]
+repl = [
   "pyperclip>=1.9.0",
   "prompt-toolkit>=3.0.50",
   "xonsh>=0.19.2",
   "psutil>=7.0.0",
 ]
+lint = [
+  "ruff>=0.9.6"
+]
 # TODO, add these with sane versions; were originally in
 # `requirements-docs.txt`..
 # docs = [