CPython 3.12.13 checkpoint #

This fixture cross-compiles ordinary static and dynamic AArch64 musl CPython runtimes and packages their standard library as Binarrow filesystem images. The generated runtime and image are intentionally kept in the repository's gitignored .tmp/cpython-3.12.13 directory rather than committed to Git.

Prerequisites:

• Zig 0.16.0
• llvm-objcopy for the dynamic fixture
• the repository Rust toolchain
• curl, make, tar, unzip, shasum, and a native C compiler

Build the host bootstrap interpreter, target interpreter, and filesystem image:

guest-tests/cpython/build.sh

The download is pinned by SHA-256. Host package discovery is disabled for the cross build so unavailable target libraries cannot leak in through the host's pkg-config. Configured dependency-free extension modules are linked into the static executable.

Run the bounded native regression:

guest-tests/cpython/verify.sh

The verification checks Python 3.12.13, installs a separately packaged multi-file project and the checksum-pinned official packaging 26.2 wheel over the standard-library snapshot, imports both filesystem-backed packages, checks the wheel's retained distribution metadata, prints their deterministic results, and validates an unhandled exception traceback with guest paths and exit status 1. package-packaging.sh keeps the wheel, unpacked contents, and generated image under .tmp. The current interpreter can take several minutes to complete this regression even when the native runner is built in release mode.

Build and verify the Phase 7 dynamic-linking checkpoint:

guest-tests/cpython/build-dynamic.sh
guest-tests/cpython/verify-dynamic.sh

The dynamic fixture reuses the pinned source and standard-library image, builds a shared libpython3.12.so, packages the selected _struct native extension, and installs the separately built guest musl dynamic linker. The verification imports _struct through CPython's normal dlopen path and uses it to encode the integer 42. The guest dynamic linker, not Binarrow, performs the shared-object search and relocations.

Run the same packaged interpreter and standard-library image in Chromium:

guest-tests/cpython/verify-browser.sh

This opt-in Playwright regression replaces the isolated browser project's filesystem snapshot with python-lib.bnfs, installs the separately generated phase5-project.bnfs and packaging-26.2.bnfs overlays, uploads python.aarch64.elf, and checks the same imports, metadata, output, traceback, and exit status. It is skipped during the normal browser suite because the generated CPython artifacts are deliberately not committed. The interpreter regression currently takes several minutes in Chromium.