fix(build): use Homebrew clang for wasm32 C build on macOS#77
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When CC is set (e.g. ccache cc), the wasm32 C/C++ build can use Apple Clang, which does not support wasm32-unknown-unknown, so the datadog-js-zstd WASM build failed. Set CC_wasm32_unknown_unknown and CXX_wasm32_unknown_unknown to Homebrew's clang so crates like zstd-sys always use a wasm32-capable compiler. Add DEVELOPMENT.md with Rust/rustup, macOS LLVM, and yarn setup steps, and move the build/test notes from README into DEVELOPMENT.md.
Overall package sizeSelf size: 37.28 MB Dependency sizes| name | version | self size | total size | |------|---------|-----------|------------|🤖 This report was automatically generated by heaviest-objects-in-the-universe |
szegedi
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Mar 3, 2026
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LGTM, I have one small suggestion.
tlhunter
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When CC is set (e.g. ccache cc), the wasm32 C/C++ build can use Apple Clang, which does not support wasm32-unknown-unknown, so the datadog-js-zstd WASM build failed. Set CC_wasm32_unknown_unknown and CXX_wasm32_unknown_unknown to Homebrew's clang so crates like zstd-sys always use a wasm32-capable compiler. Add DEVELOPMENT.md with Rust/rustup, macOS LLVM, and yarn setup steps, and move the build/test notes from README into DEVELOPMENT.md.
tlhunter
pushed a commit
that referenced
this pull request
Mar 20, 2026
When CC is set (e.g. ccache cc), the wasm32 C/C++ build can use Apple Clang, which does not support wasm32-unknown-unknown, so the datadog-js-zstd WASM build failed. Set CC_wasm32_unknown_unknown and CXX_wasm32_unknown_unknown to Homebrew's clang so crates like zstd-sys always use a wasm32-capable compiler. Add DEVELOPMENT.md with Rust/rustup, macOS LLVM, and yarn setup steps, and move the build/test notes from README into DEVELOPMENT.md.
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Summary
Fixes the full
yarn buildon macOS when a customCC(e.g.ccache cc) is set, and adds a single place for development setup and build instructions.Changes
WASM build on macOS — The
datadog-js-zstdWASM crate useszstd-sys, which compiles C code forwasm32-unknown-unknown. IfCCpoints at Apple Clang or a wrapper likeccache cc, that compiler doesn’t support the wasm32 triple and the build fails with "No available targets are compatible with triple 'wasm32-unknown-unknown'". Inscripts/build-wasm.js, we now setCC_wasm32_unknown_unknownandCXX_wasm32_unknown_unknownto Homebrew’s clang so the wasm32 C/C++ build always uses a supported compiler, without changing behavior on Linux or for people who already rely on PATH.Docs — Added
DEVELOPMENT.mdwith step-by-step setup (rustup, PATH,wasm32-unknown-unknown, macOSbrew install llvm,yarn install) and the build/test commands. Removed the duplicate build section fromREADME.mdand pointed toDEVELOPMENT.mdfor contributing/setup.