uv2nix

NixOS compatible
Let's see if it works in GH actions

Author: ianepreston

.envrc

@@ -1,3 +1 @@
-use flake . --impure
-uv sync
-source .venv/bin/activate
+use flake

Makefile

@@ -1,13 +1,13 @@
 .PHONY: docs
 test:
-	nix develop --impure . -c uv run pre-commit run --all-files --show-diff-on-failure
-	nix develop --impure . -c uv run ruff check .
-	nix develop --impure . -c uv run --managed-python --python 3.10 coverage run -m pytest
-	nix develop --impure . -c uv run --managed-python --python 3.11 coverage run -m pytest
-	nix develop --impure . -c uv run --managed-python --python 3.12 coverage run -m pytest
-	nix develop --impure . -c uv run --managed-python --python 3.13 coverage run -m pytest
-	nix develop --impure . -c uv run coverage report
+	nix develop --impure . -c pre-commit run --all-files --show-diff-on-failure
+	nix develop --impure . -c ruff check .
+	nix develop --impure .#python310 -c coverage run -m pytest
+	nix develop --impure .#python311 -c coverage run -m pytest
+	nix develop --impure .#python312 -c coverage run -m pytest
+	nix develop --impure .#python313 -c coverage run -m pytest
+	nix develop --impure . -c coverage report
 safety:
-	nix develop --impure . -c uv run safety check --file=uv.lock --full-report
+	nix develop --impure . -c safety check --file=uv.lock --full-report
 docs:
-	nix develop --impure . -c uv run sphinx-build docs/source docs/_build
+	nix develop --impure . -c sphinx-build docs/source docs/_build

flake.lock

@@ -1,40 +1,133 @@
 {
-  description = "A Nix flake-based development environment for working with stats_can";
+  description = "Stats Can flake using uv2nix";
 
-  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+    pyproject-nix = {
+      url = "github:pyproject-nix/pyproject.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    uv2nix = {
+      url = "github:pyproject-nix/uv2nix";
+      inputs.pyproject-nix.follows = "pyproject-nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    pyproject-build-systems = {
+      url = "github:pyproject-nix/build-system-pkgs";
+      inputs.pyproject-nix.follows = "pyproject-nix";
+      inputs.uv2nix.follows = "uv2nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
 
   outputs =
-    { self, nixpkgs }:
+    {
+      self,
+      nixpkgs,
+      uv2nix,
+      pyproject-nix,
+      pyproject-build-systems,
+      ...
+    }:
     let
-      supportedSystems = [
-        "x86_64-linux"
-        "aarch64-linux"
-        "x86_64-darwin"
-        "aarch64-darwin"
-      ];
-      forEachSupportedSystem =
-        f:
-        nixpkgs.lib.genAttrs supportedSystems (
-          system:
-          f {
-            pkgs = import nixpkgs {
-              inherit system;
-              config.allowUnfree = true;
-            };
-          }
-        );
+      inherit (nixpkgs) lib;
+
+      workspace = uv2nix.lib.workspace.loadWorkspace { workspaceRoot = ./.; };
+
+      overlay = workspace.mkPyprojectOverlay {
+        sourcePreference = "wheel";
+      };
+
+      pyprojectOverrides = _final: _prev: {
+        # Implement build fixups here.
+      };
+
+      pkgs = nixpkgs.legacyPackages.x86_64-linux;
+
+      pythonVersions = {
+        python310 = pkgs.python310;
+        python311 = pkgs.python311;
+        python312 = pkgs.python312;
+        python313 = pkgs.python313;
+        default = pkgs.python313; # This will create a 'default' shell
+      };
+
+      # --- CHANGED: A function to generate a dev shell for a given Python version ---
+      # This function encapsulates all the logic that was previously hardcoded for a single Python version.
+      mkPythonDevShell =
+        python:
+        let
+          # 'pythonSet' is now defined inside this function, using the 'python' argument.
+          pythonSet =
+            (pkgs.callPackage pyproject-nix.build.packages {
+              inherit python;
+            }).overrideScope
+              (
+                lib.composeManyExtensions [
+                  pyproject-build-systems.overlays.default
+                  overlay
+                  pyprojectOverrides
+                ]
+              );
+
+          # The rest of the shell-building logic is also moved inside.
+          editableOverlay = workspace.mkEditablePyprojectOverlay {
+            root = "$REPO_ROOT";
+          };
+
+          editablePythonSet = pythonSet.overrideScope (
+            lib.composeManyExtensions [
+              editableOverlay
+              (final: prev: {
+                stats-can = prev.stats-can.overrideAttrs (old: {
+                  src = lib.fileset.toSource {
+                    root = old.src;
+                    fileset = lib.fileset.unions [
+                      (old.src + "/pyproject.toml")
+                      (old.src + "/README.md")
+                      (old.src + "/src/stats_can/__init__.py")
+                    ];
+                  };
+                  nativeBuildInputs =
+                    old.nativeBuildInputs
+                    ++ final.resolveBuildSystem {
+                      editables = [ ];
+                    };
+                });
+              })
+            ]
+          );
+
+          virtualenv = editablePythonSet.mkVirtualEnv "stats-can-dev-env" workspace.deps.all;
+
+        in
+        pkgs.mkShell {
+          packages = [
+            virtualenv
+            pkgs.uv
+          ];
+
+          env = {
+            UV_NO_SYNC = "1";
+            # Use the 'python' argument to set the interpreter path.
+            UV_PYTHON = python.interpreter;
+            UV_PYTHON_DOWNLOADS = "never";
+          };
+
+          shellHook = ''
+            unset PYTHONPATH
+            export REPO_ROOT=$(git rev-parse --show-toplevel)
+          '';
+        };
+
     in
     {
-      devShells = forEachSupportedSystem (
-        { pkgs }:
-        {
-          default = pkgs.mkShell {
-            packages = with pkgs; [
-              uv
-              migrate-to-uv
-            ];
-          };
-        }
-      );
+      # --- CHANGED: Generate multiple dev shells using lib.mapAttrs ---
+      # We map over the 'pythonVersions' set. For each entry, we call our 'mkPythonDevShell' function.
+      # The key of the entry (e.g., "python312") becomes the name of the shell.
+      devShells.x86_64-linux = lib.mapAttrs (_name: pythonPkg: mkPythonDevShell pythonPkg) pythonVersions;
     };
 }