Hasty Briefsbeta

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I made a build visualizer to understand Bun's compile times

3 days ago
  • buildprof is an open-source Linux tool that records process trees and visualizes build timelines.
  • It helped analyze why Bun's Zig-era build was slower than its Rust-era build due to Full LTO and a monolithic single module.
  • Switching to ThinLTO and rebuilding WebKit reduced the Zig build time from 24 to 15 minutes.
  • The remaining performance gap is structural: Rust splits compilation across >90 crates while Zig uses a single module.
  • buildprof uses ptrace for process tracking and seccomp for file I/O monitoring, with low overhead.
  • The UI is a soft fork of Perfetto, offering extensible timeline and dependency arrows.