feat: enable V8 code cache for host-platform binaries#8
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When the build host is also a target platform, enable useCodeCache in the SEA config for that platform's binary. Code cache pre-compiles the JS into V8 bytecode at build time, saving ~15% startup time. Since code cache is CPU-architecture-specific, it can't be used for cross-compiled binaries. When building multiple targets that include the host platform, two blobs are generated: - Base blob (no code cache) for cross-compiled targets - Code-cache blob for the host platform binary When building for a single platform that matches the host (the common local-dev case), only one blob is generated with code cache enabled.
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This was referenced May 22, 2026
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Updates fossilize to v0.6.0 which automatically enables V8 code cache for binaries matching the build host platform. **Impact:** The linux-x64 binary (built on ubuntu-latest in CI) gets ~15% faster startup (~740ms vs ~870ms) from pre-compiled V8 bytecode. Cross-compiled binaries (darwin, windows, linux-arm64) are unaffected — code cache is CPU-architecture-specific. See BYK/fossilize#8 for the fossilize change.
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Summary
When the build host is also a target platform, enable
useCodeCachein the SEA config for that platform's binary. V8 code cache pre-compiles the JS into bytecode at build time, saving ~15% startup time.Since code cache is CPU-architecture-specific, it can't be used for cross-compiled binaries. This PR handles all three scenarios:
Scenarios
--single)How it works
When cross-compiling multiple targets AND the host is one of them:
When building for a single platform that matches the host (common local-dev case), only one blob is generated with code cache enabled.
Benchmark (Sentry CLI, ~4MB CJS bundle, linux-x64)
~130ms / ~15% improvement with zero downsides for same-platform binaries.