## Summary
- Update LLVM version references across build scripts, Dockerfiles, CI,
Nix configs, and documentation
- Fix LLVM 21 `-Wcharacter-conversion` errors in WebKit bindings:
- `EncodingTables.h`: pragma for intentional char32_t/char16_t
comparisons
- `TextCodecCJK.cpp`: widen `gb18030AsymmetricEncode` param to char32_t
- `URLPatternParser`: widen `isValidNameCodepoint` param to char32_t,
cast for `startsWith`
- Fix `__libcpp_verbose_abort` noexcept mismatch (LLVM 21 uses
`_NOEXCEPT`)
- Fix dangling pointer in `BunJSCModule.h` (`toCString` temporary
lifetime)
- Remove `useMathSumPreciseMethod` (removed upstream in JSC)
**Before merging:** Merge https://github.com/oven-sh/WebKit/pull/153
first, then update `WEBKIT_VERSION` in `cmake/tools/SetupWebKit.cmake`
to point to the merged commit.
## Test plan
- [ ] Build bun debug on macOS with LLVM 21
- [ ] Build bun on Linux (glibc)
- [ ] Build bun on Linux (musl)
- [ ] Build bun on Windows
- [ ] Run test suite
Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
## 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>
Provides a Nix flake as an alternative to `scripts/bootstrap.sh` for
setting up the Bun development environment.
## What's included:
- **flake.nix**: Full development environment with all dependencies from
bootstrap.sh
- LLVM 19, CMake 3.30+, Node.js 24, Rust, Go
- Build tools: ninja, ccache, pkg-config, make
- Chromium dependencies for Puppeteer testing
- gdb for core dump debugging
- **shell.nix**: Simple wrapper for `nix-shell` usage
- **cmake/CompilerFlags.cmake**: Nix compatibility fixes
- Disable zstd debug compression (Nix's LLVM not built with zstd)
- Set _FORTIFY_SOURCE=0 for -O0 debug builds
- Downgrade _FORTIFY_SOURCE warning to not error
## Usage:
```bash
nix-shell
export CMAKE_SYSTEM_PROCESSOR=$(uname -m)
bun bd
```
## Verified working:
✅ Successfully compiles Bun debug build
✅ Binary tested: `./build/debug/bun-debug --version` → 1.2.24-debug
✅ All dependencies from bootstrap.sh included
## Advantages:
- Fully isolated (no sudo required)
- 100% reproducible dependency versions
- Fast setup with binary caching
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
