D706 - CI tests macOS as x86-64

Status: assumed Date: 2026-09-19

The CI test job on the macOS runner builds and tests x86_64-apple-darwin, the triple the release workflow ships, with the test binaries running under the runner's x86-64 translation layer. The ABI boundary is not gated off aarch64.

Why: guest code is x86-64 and runs natively, so the only macOS build that can run a guest is x86-64, and the boundary's sysv64 functions do not compile for aarch64. If the translation layer is unavailable to the job, an x86-64 runner tests the same triple natively.

Rejected:

• Gating the 28 sysv64 sites and the entry assembly by architecture: real work whose product is a build that cannot run a guest.
• Building natively for aarch64: does not compile.