From 3d8eb0e6d1aa8c7e52012d73f69ddf0a02445698 Mon Sep 17 00:00:00 2001
From: Fabian Affolter <mail@fabian-affolter.ch>
Date: Mon, 4 May 2026 12:29:02 +0200
Subject: [PATCH] python3Packages.wasmtime: init at 44.0.0

Python WebAssembly runtime powered by Wasmtime

https://github.com/bytecodealliance/wasmtime-py
---
 .../python-modules/wasmtime/default.nix       | 83 +++++++++++++++++++
 pkgs/top-level/python-packages.nix            |  2 +
 2 files changed, 85 insertions(+)
 create mode 100644 pkgs/development/python-modules/wasmtime/default.nix

diff --git a/pkgs/development/python-modules/wasmtime/default.nix b/pkgs/development/python-modules/wasmtime/default.nix
new file mode 100644
index 000000000000..0d6385e2d5ee
--- /dev/null
+++ b/pkgs/development/python-modules/wasmtime/default.nix
@@ -0,0 +1,83 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchFromGitHub,
+  python,
+  pkgs,
+  pycparser,
+  pytest-mypy,
+  pytestCheckHook,
+  setuptools-git-versioning,
+  setuptools,
+  writableTmpDirAsHomeHook,
+}:
+
+buildPythonPackage (finalAttrs: {
+  pname = "wasmtime";
+  version = "44.0.0";
+  pyproject = true;
+
+  src = fetchFromGitHub {
+    owner = "bytecodealliance";
+    repo = "wasmtime-py";
+    tag = finalAttrs.version;
+    hash = "sha256-7K0j4jMsRB7/wNIj0pXxFTy0y7aN37wgCD1XKM92Ayw=";
+  };
+
+  postPatch = ''
+    substituteInPlace pyproject.toml \
+      --replace-fail "setuptools-git-versioning>=2.0,<3" "setuptools-git-versioning" \
+      --replace-fail 'build-backend = "backend"' 'build-backend = "setuptools.build_meta"'
+
+    substituteInPlace ci/cbindgen.py \
+      --replace-fail "'-D__builtin_va_list=int'," "'-D__builtin_va_list=int', '-Dnullptr_t=void*',"
+
+    sed -i '/^backend-path = \[/,/^\]/d' pyproject.toml
+
+    # Use nixpkgs' wasmtime instead of downloading prebuilt C API artifacts.
+    mkdir -p wasmtime/linux-x86_64 wasmtime/linux-aarch64
+    ln -s ${lib.getLib pkgs.wasmtime}/lib/libwasmtime.so wasmtime/linux-x86_64/_libwasmtime.so
+    ln -s ${lib.getLib pkgs.wasmtime}/lib/libwasmtime.so wasmtime/linux-aarch64/_libwasmtime.so
+  '';
+
+  build-system = [
+    setuptools
+    setuptools-git-versioning
+  ];
+
+  buildInputs = [ pkgs.wasmtime ];
+
+  postInstall = ''
+    # Ensure the installed module can find the shared library at runtime
+    mkdir -p "$out/${python.sitePackages}/wasmtime/linux-x86_64"
+    mkdir -p "$out/${python.sitePackages}/wasmtime/linux-aarch64"
+    ln -sf ${lib.getLib pkgs.wasmtime}/lib/libwasmtime.so "$out/${python.sitePackages}/wasmtime/linux-x86_64/_libwasmtime.so"
+    ln -sf ${lib.getLib pkgs.wasmtime}/lib/libwasmtime.so "$out/${python.sitePackages}/wasmtime/linux-aarch64/_libwasmtime.so"
+  '';
+
+  nativeCheckInputs = [
+    pycparser
+    pytest-mypy
+    pytestCheckHook
+    writableTmpDirAsHomeHook
+  ];
+
+  disabledTestPaths = [
+    "ci/cbindgen.py"
+  ];
+
+  pythonImportsCheck = [ "wasmtime" ];
+
+  preCheck = ''
+    # cbindgen.py checks bindings against C headers during test collection.
+    ln -s ${lib.getDev pkgs.wasmtime}/include wasmtime/include
+  '';
+
+  meta = {
+    description = "Python WebAssembly runtime powered by Wasmtime";
+    homepage = "https://github.com/bytecodealliance/wasmtime-py";
+    changelog = "https://github.com/bytecodealliance/wasmtime-py/releases/tag/{${finalAttrs.src.tag}}";
+    license = lib.licenses.asl20;
+    maintainers = with lib.maintainers; [ fab ];
+  };
+})
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 0f03e26a4ce5..626f12dc1151 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -21071,6 +21071,8 @@ self: super: with self; {
 
   wasmerPackages = lib.recurseIntoAttrs (callPackage ../development/python-modules/wasmer { });
 
+  wasmtime = callPackage ../development/python-modules/wasmtime { };
+
   wasserstein = callPackage ../development/python-modules/wasserstein { };
 
   wassima = callPackage ../development/python-modules/wassima { };