## Summary
Add CI steps that verify baseline builds don't use CPU instructions
beyond their target. Uses QEMU user-mode emulation with restricted CPU
features — any illegal instruction causes SIGILL and fails the build.
## Platforms verified
| Build Target | QEMU Command | What it catches |
|---|---|---|
| `linux-x64-baseline` (glibc) | `qemu-x86_64 -cpu Nehalem` | AVX, AVX2,
AVX512 |
| `linux-x64-musl-baseline` | `qemu-x86_64 -cpu Nehalem` | AVX, AVX2,
AVX512 |
| `linux-aarch64` (glibc) | `qemu-aarch64 -cpu cortex-a35` | LSE
atomics, SVE, dotprod |
| `linux-aarch64-musl` | `qemu-aarch64 -cpu cortex-a35` | LSE atomics,
SVE, dotprod |
## How it works
Each verify step:
1. Downloads the built binary artifact from the `build-bun` step
2. Installs `qemu-user-static` on-the-fly (dnf/apk/apt-get)
3. Runs two smoke tests under QEMU with restricted CPU features:
- `bun --version` — validates startup, linker, static init code
- `bun -e eval` — validates JSC initialization and basic execution
4. Hard fails on SIGILL (exit code 132)
The verify step runs in the build group after `build-bun`, with a
5-minute timeout.
## Known issue this will surface
**mimalloc on aarch64**: Built with `MI_OPT_ARCH=ON` which adds
`-march=armv8.1-a`, enabling LSE atomics. This will SIGILL on
Cortex-A35/A53 CPUs. The aarch64 verify steps are expected to fail
initially, confirming the test catches real issues. Fix can be done
separately in `cmake/targets/BuildMimalloc.cmake`.
## Summary
- Remove sccache support entirely, use ccache only
- Missing ccache no longer fails the build (just skips caching)
- Remove S3 distributed cache support
## Changes
- Remove `cmake/tools/SetupSccache.cmake` and S3 distributed cache
support
- Simplify `CMakeLists.txt` to only use ccache
- Update `SetupCcache.cmake` to not fail when ccache is missing
- Replace sccache with ccache in bootstrap scripts (sh, ps1)
- Update `.buildkite/Dockerfile` to install ccache instead of sccache
- Update `flake.nix` and `shell.nix` to use ccache
- Update documentation (CONTRIBUTING.md, contributing.mdx,
building-windows.mdx)
- Remove `scripts/build-cache/` directory (was only for sccache S3
access)
## Test plan
- [x] Build completes successfully with `bun bd`
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
## Summary
- Implements automated Windows code signing for x64 and x64-baseline
builds
- Integrates DigiCert KeyLocker for secure certificate management
- Adds CI/CD pipeline support for signing during builds
## Changes
- Added `.buildkite/scripts/sign-windows.sh` script for automated
signing
- Updated CMake configurations to support signing workflow
- Modified build scripts to integrate signing step
## Testing
- Script tested locally with manual signing process
- Successfully signed test binaries at:
- `C:\Builds\bun-windows-x64\bun.exe`
- `C:\Builds\bun-windows-x64-baseline\bun.exe`
## References
Uses DigiCert KeyLocker tools for Windows signing
## Next Steps
- Validate Buildkite environment variables in CI
- Test full pipeline in CI environment
---------
Co-authored-by: Jarred Sumner <jarred@bun.sh>
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
this instance type was reported to be our 1st most expensive per aws
bill
----
before:
x64-linux: 19.5m
arm64-linux: 14m
x64-musl: 16.3m
arm64-musl: 13.3m
x64-windows: 2m
after:
x64-linux: 20.3m
arm64-linux: 15.3m
x64-musl: 16m
arm64-musl: 13.5m
x64-windows: 2.5m
