Add nix flake

flake.lock

@@ -0,0 +1,11 @@
+{
+    "inputs": {
+        "nixpkgs": {
+            "inputs": {},
+            "narHash": "sha256-Y5ZOTgInrYYoas3vM8uTPLA2DvFI9YoI6haftIKl9go=",
+            "originalUrl": "nixpkgs",
+            "url": "github:edolstra/nixpkgs/015c9ec3372e328ea6742b409a1e9aa26dab2b31"
+        }
+    },
+    "version": 3
+}

flake.nix

@@ -0,0 +1,28 @@
+{
+  description = "Poetry2nix flake";
+
+  edition = 201909;
+
+  outputs = { self, nixpkgs }: let
+    # TODO: There must be a better way to provide arch-agnostic flakes..
+    systems = [ "x86_64-linux" "i686-linux" "x86_64-darwin" "aarch64-linux" ];
+    forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f system);
+    # Memoize nixpkgs for different platforms for efficiency.
+    nixpkgsFor = forAllSystems (system:
+      import nixpkgs {
+        inherit system;
+        overlays = [ self.overlay ];
+      }
+    );
+
+  in {
+
+    overlay = import ./overlay.nix;
+
+    # TODO: I feel like `packages` is the wrong place for the poetry2nix attr
+    packages = forAllSystems (system: {
+      inherit (nixpkgsFor.${system}) poetry poetry2nix;
+    });
+
+  };
+}

pkgs/poetry/default.nix

@@ -34,7 +34,7 @@ poetry2nix.mkPoetryPackage {
     mkdir -p $out/bin
     cat > $out/bin/poetry <<EOF
     #!${runtimeShell}
-    export PYTHONPATH=$PYTHONPATH
+    export PYTHONPATH=$out/lib/${python.libPrefix}/site-packages:$PYTHONPATH
     exec ${python}/bin/python -m poetry "\$@"
     EOF
     chmod +x $out/bin/poetry