Recipe to build pydantic-core (required for Pydantic 2)

server/pypi/README.md

@@ -59,7 +59,8 @@ these can be installed using your distribution. Some of them have special entrie
   [here](https://github.com/mzakharo/android-gfortran/releases/tag/r21e). Create a
   `fortran` subdirectory in the same directory as this README, and unpack the .bz2 files
   into it.
-* `rust`: `rustup` must be on the PATH.
+* `rust`: `rustup` must be on the PATH. One can set `PYO3_NO_PYTHON=1` in `script_env:` to build without a Python interpreter (https://pyo3.rs/main/building-and-distribution#building-abi3-extensions-without-a-python-interpreter). 
+  Building with a Python interpreter is supported only for Python 3.13 and above.
 
 
 ## Building a package

server/pypi/build-wheel.py

@@ -135,6 +135,7 @@ def unpack_and_build(self):
         self.src_dir = f"{self.build_dir}/src"
         self.build_env = f"{self.build_dir}/env"
         self.host_env = f"{self.build_dir}/requirements"
+        self.chaquopy_dir = f"{self.host_env}/chaquopy"
 
         if self.no_unpack:
             log("Reusing existing build directory due to --no-unpack")
@@ -249,6 +250,10 @@ def version_key(ver):
         if len(zips) != 1:
             raise CommandError(f"Found {len(zips)} {self.abi} ZIPs in {target_version_dir}")
         self.target_zip = zips[0]
+        zips = glob(f"{target_version_dir}/target-*-stdlib.zip")
+        if len(zips) != 1:
+            raise CommandError(f"Found {len(zips)} stdlib ZIPs in {target_version_dir}")
+        self.std_lib_zip = zips[0]
 
     def create_build_env(self):
         python_ver = self.python or ".".join(map(str, sys.version_info[:2]))
@@ -502,9 +507,11 @@ def create_dummy_libs(self):
         for name in ["pthread", "rt"]:
             run(f"{os.environ['AR']} rc {self.host_env}/chaquopy/lib/lib{name}.a")
 
+    def extract_stdlib(self):
+        run(f"unzip -q -d {self.chaquopy_dir}/lib {self.std_lib_zip}")
+
     def extract_target(self):
-        chaquopy_dir = f"{self.host_env}/chaquopy"
-        run(f"unzip -q -d {chaquopy_dir} {self.target_zip} include/* jniLibs/*")
+        run(f"unzip -q -d {self.chaquopy_dir} {self.target_zip} include/* jniLibs/*")
 
         # Only include OpenSSL and SQLite in the environment if the recipe requests
         # them. This affects grpcio, which provides its own copy of BoringSSL, and gets
@@ -517,7 +524,7 @@ def extract_target(self):
                 self.meta["requirements"]["host"].remove(name)
             except ValueError:
                 for pattern in [f"include/{includes}", f"jniLibs/{self.abi}/{libs}"]:
-                    run(f"rm -r {chaquopy_dir}/{pattern}", shell=True)
+                    run(f"rm -r {self.chaquopy_dir}/{pattern}", shell=True)
 
         # When building packages that could be loaded by older versions of Chaquopy,
         # i.e non-Python packages, and Python packages for 3.12 and older:
@@ -533,7 +540,7 @@ def extract_target(self):
         #
         # When building only for Python 3.13 and newer, we should use the _python suffix
         # so our wheels are compatible with any other Python on Android distributions.
-        lib_dir = f"{chaquopy_dir}/jniLibs/{self.abi}"
+        lib_dir = f"{self.chaquopy_dir}/jniLibs/{self.abi}"
         for name in ["crypto", "ssl", "sqlite3"]:
             python_name = f"lib{name}_python.so"
             chaquopy_name = f"lib{name}_chaquopy.so"
@@ -547,8 +554,10 @@ def extract_target(self):
                     run(f"patchelf --set-soname {chaquopy_name} "
                         f"{lib_dir}/{chaquopy_name}")
 
-        run(f"mv {chaquopy_dir}/jniLibs/{self.abi}/* {chaquopy_dir}/lib", shell=True)
-        run(f"rm -r {chaquopy_dir}/jniLibs")
+        run(f"mv {self.chaquopy_dir}/jniLibs/{self.abi}/* {self.chaquopy_dir}/lib", shell=True)
+        run(f"rm -r {self.chaquopy_dir}/jniLibs")
+
+        self.extract_stdlib()
 
     def build_with_script(self, build_script):
         prefix_dir = f"{self.build_dir}/prefix"
@@ -659,18 +668,18 @@ def get_rust_env_vars(self, env):
         env.update({
             "RUSTFLAGS": f"-C linker={env['CC']} -L native={self.host_env}/chaquopy/lib",
             "CARGO_BUILD_TARGET": tool_prefix,
-
-            # Normally PyO3 requires sysconfig modules, which are not currently
-            # available in the `target` packages for Python 3.12 and older. However,
-            # since PyO3 0.16.4, it's possible to compile abi3 modules without sysconfig
-            # modules. This only requires packages to specify the minimum python
-            # compatibility version via one of the "abi3-py*" features (e.g.
-            # abi3-py310). Doing this requires the "-L native" flag in RUSTFLAGS above.
-            # https://pyo3.rs/main/building-and-distribution#building-abi3-extensions-without-a-python-interpreter
-            "PYO3_NO_PYTHON": "1",
             "PYO3_CROSS": "1",
             "PYO3_CROSS_PYTHON_VERSION": self.python,
         })
+        # Normally PyO3 requires sysconfig modules, which are not currently
+        # available in the `target` packages for Python 3.12 and older, but are available on Python 3.13.
+        # However, since PyO3 0.16.4, it's possible to compile abi3 modules without sysconfig
+        # modules. This only requires packages to specify the minimum python
+        # compatibility version via one of the "abi3-py*" features (e.g.
+        # abi3-py310). Doing this requires the "-L native" flag in RUSTFLAGS above.
+        # https://pyo3.rs/main/building-and-distribution#building-abi3-extensions-without-a-python-interpreter
+        if 'PYO3_NO_PYTHON' not in env:
+            env["PYO3_CROSS_LIB_DIR"] = self.chaquopy_dir
 
     @contextmanager
     def env_vars(self):
@@ -686,8 +695,6 @@ def env_vars(self):
 
         if self.needs_python:
             self.get_python_env_vars(env, pypi_env)
-        if "rust" in self.non_python_build_reqs:
-            self.get_rust_env_vars(env)
 
         env.update({
             # TODO: make everything use HOST instead, and remove this.
@@ -707,6 +714,9 @@ def env_vars(self):
             key, value = var.split("=", 1)
             env[key] = value
 
+        if "rust" in self.non_python_build_reqs:
+            self.get_rust_env_vars(env)
+
         # We do this unconditionally, because we don't know whether the package requires
         # CMake (it may be listed in the pyproject.toml build-system requires).
         self.generate_cmake_toolchain(env)

server/pypi/packages/cryptography/meta.yaml

@@ -2,6 +2,10 @@ package:
   name: cryptography
   version: "42.0.8"
 
+build:
+  script_env:
+    - PYO3_NO_PYTHON=1
+
 requirements:
   build:
     - rust

server/pypi/packages/pydantic-core/meta.yaml

@@ -0,0 +1,9 @@
+package:
+  name: pydantic-core
+  version: "2.41.4"
+
+requirements:
+  build:
+    - rust
+  host:
+    - python