python3Packages.ty: init at 0.0.20

Similar to `python3Packages.ruff` and `python3Packages.uv`, the Python
module for ty allows for the ty binary to be searched for, e.g. for
subprocess CLI invocations.

This derivation uses the same tricks to speedup its build by referencing
the nixpkgs ty binary instead of rebuilding from scratch.

pkgs/development/python-modules/ty/default.nix

@@ -0,0 +1,46 @@
+{
+  buildPythonPackage,
+  hatchling,
+  lib,
+  ty,
+}:
+
+buildPythonPackage {
+  inherit (ty)
+    pname
+    version
+    src
+    meta
+    ;
+  pyproject = true;
+
+  build-system = [ hatchling ];
+
+  postPatch =
+    # Add the path to the ty binary as a fallback after other path search methods have been exhausted
+    ''
+      substituteInPlace python/ty/_find_ty.py \
+        --replace-fail \
+        'sysconfig.get_path("scripts", scheme=_user_scheme()),' \
+        'sysconfig.get_path("scripts", scheme=_user_scheme()), "${baseNameOf (lib.getExe ty)}",'
+    ''
+    # Sidestep the maturin build system in favour of reusing the binary already built by nixpkgs,
+    # to avoid rebuilding the ty binary for every active python package set.
+    + ''
+      substituteInPlace pyproject.toml \
+        --replace-fail 'requires = ["maturin>=1.0,<2.0"]' 'requires = ["hatchling"]' \
+        --replace-fail 'build-backend = "maturin"' 'build-backend = "hatchling.build"'
+
+      cat >> pyproject.toml <<EOF
+      [tool.hatch.build]
+      packages = ['python/ty']
+
+      EOF
+    '';
+
+  postInstall = ''
+    mkdir -p $out/bin && ln -s ${lib.getExe ty} $out/bin/ty
+  '';
+
+  pythonImportsCheck = [ "ty" ];
+}

pkgs/top-level/python-packages.nix

@@ -19685,6 +19685,8 @@ self: super: with self; {
 
   txzmq = callPackage ../development/python-modules/txzmq { };
 
+  ty = callPackage ../development/python-modules/ty { inherit (pkgs) ty; };
+
   type-infer = callPackage ../development/python-modules/type-infer { };
 
   typechecks = callPackage ../development/python-modules/typechecks { };