Add native win-arm64 support

[baszalmstra]

Builds py-rattler natively on GitHub's windows-11-arm runners. The only recipe change beyond the CI setup is one environment variable that aws-lc-sys needs on that platform.

aws-lc-sys

aws-lc-sys does not build on win-arm64. cl.exe cannot assemble the generated win-aarch64 perlasm, so it skips the files and the link then fails on objects that were never produced:

cl : Command line warning D9024 : unrecognized source file type '...\generated-src/win-aarch64/crypto/.../chacha-armv8.S'
cl : Command line warning D9027 : source file '...' will be ignored
LINK : fatal error LNK1181: cannot open input file '...\out\8243065ad0646c1d-chacha-armv8.o'

aws-lc-sys knows about this and since 0.40.0 (aws/aws-lc-rs#1060) locates clang-cl in the Visual Studio installation by itself. That only happens when CC is unset:

if target_os() == "windows" && target_arch() == "aarch64" && target_env() == "msvc"
    && get_crate_cc().is_none()
{
    if let Some(clang_cl) = find_clang_cl() { set_env_for_target("CC", clang_cl); }

The conda-forge activation sets CC=cl.exe, so the discovery is skipped and we land back on the one compiler that cannot build this target. Setting AWS_LC_SYS_CC_aarch64_pc_windows_msvc=clang-cl.exe takes priority over CC and gets us to the same compiler upstream would have picked. The variable is target-scoped, so it is inert everywhere else. The guard is unchanged in 0.44.0, so bumping the crate does not help.

conda-forge/uv-feedstock#369 and conda-forge/pixi-build-python-feedstock#27 hit the same problem and route around it with AWS_LC_SYS_CMAKE_BUILDER=1, whose cmake builder picks the ClangCL toolset. That works too, but needs a cmake for win-arm64 (conda-forge/cmake-feedstock#267) and there is nothing else in this recipe that wants cmake.

Blocked on

• Support Windows ARM64 platform ujson-feedstock#64 — the abi3audit test needs native builds of transitive dependencies such as ujson and Brotli.

Merged and no longer blocking: conda-forge/conda-smithy#2622, conda-forge/cargo-bundle-licenses-feedstock#29, conda-forge/cargo-auditable-feedstock#11, conda-forge/maturin-feedstock#180, conda-forge/python-abi3-feedstock#11.

Validation

• conda-smithy lint --conda-forge ., and a second rerender produces no changes.
• An experimental native job passed with this same clang-cl override, after temporarily provisioning the unavailable tooling from win-64 under emulation. It confirmed that py-rattler compiles, packages, imports and passes its ABI audit natively on win-arm64. Those bootstrap workarounds are intentionally not part of this PR.

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/recipe.yaml) and found it was in an excellent condition.

[pavelzw]

won't this have the same issues as conda-forge/rattler-build-feedstock#158 ?

[baszalmstra]

We are now using reqwest 0.13 so I hope that will solve the issue

[baszalmstra]

Blocked on conda-forge/cross-python-feedstock#95

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/recipe.yaml) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe/recipe.yaml:

• ℹ️ This recipe builds a Python version-independent (abi3) package but does not run abi3audit in its tests. abi3 extension modules are built once and installed on every later Python, so accidental use of non-abi3 CPython API is only caught at runtime. Consider auditing the built extension modules, as in the abi3 example recipe:

tests:
  - requirements:
      run:
        - abi3audit
    script:
      - if: unix
        then: abi3audit $SP_DIR/mypackage.abi3.so -s -v --assume-minimum-abi3 ${{ python_min }}
        else: abi3audit %SP_DIR%/mypackage.pyd -s -v --assume-minimum-abi3 ${{ python_min }}

• ℹ️ This recipe handles the site-packages directory manually, either by defining SP_DIR itself or by hardcoding a path such as %PREFIX%\Lib\site-packages. rattler-build now defines $SP_DIR (%SP_DIR% on Windows), so the manual definition can be removed and hardcoded paths replaced with $SP_DIR / %SP_DIR%.

_{This message was generated by GitHub Actions workflow run https://github.com/conda-forge/conda-forge-webservices/actions/runs/31332937382. Examine the logs at this URL for more detail.}

[jaimergp]

cargo failing with:

 │ │   LINK : fatal error LNK1181: cannot open input file '%SRC_DIR%\py-rattler\target\aarch64-pc-windows-msvc\release\build\aws-lc-sys-117afccec554a780\out\8243065ad0646c1d-chacha-armv8.o'
 │ │   --- stderr
 │ │   error occurred in cc-rs: command did not execute successfully (status code exit code: 1181): "C:\\Program Files\\Microsoft Visual Studio\\2022\\Enterprise\\VC\\Tools\\MSVC\\14.44.35207\\bin\\HostARM64\\ARM64\\lib.exe" "-out:C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\libaws_lc_0_41_0_crypto.a" "-nologo" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\libaws_lc_0_41_0_crypto.a" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_attrib.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_crl.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_exten.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_name.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_pubkey.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_req.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_sig.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_spki.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_val.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_x509.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\282bd74e55216496-x_x509a.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e6a0bdd2c14b502f-err_data.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\8243065ad0646c1d-chacha-armv8.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\0da7edcab2c95e21-chacha20_poly1305_armv8.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-aesv8-armx.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-aesv8-gcm-armv8-unroll8.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-aesv8-gcm-armv8.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-armv8-mont.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-bn-armv8.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-ghash-neon-armv8.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-ghashv8-armx.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-keccak1600-armv8.o" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\target\\aarch64-pc-windows-msvc\\release\\build\\aws-lc-sys-117afccec554a780\\out\\e4e62a10169d0f57-md5-armv8.o"
 │ │ 💥 maturin failed
 │ │   Caused by: Failed to build a native library through cargo
 │ │   Caused by: Cargo build finished with "exit code: 101": `"cargo-auditable-wrapper.bat" "rustc" "--jobs" "1" "--profile" "release" "--features" "native-tls" "--no-default-features" "--target" "aarch64-pc-windows-msvc" "--message-format" "json-render-diagnostics" "-v" "--manifest-path" "C:\\bld\\bld\\rattler-build_py-rattler_1786011991\\work\\py-rattler\\Cargo.toml" "--lib" "--" "-C" "strip=symbols"`

[pavelzw]

depends on conda-forge/cmake-feedstock#267

[pavelzw]

╰─▶ Cannot solve the request because of: No candidates were found for make