verify

name	verify
description	Verify a Bun runtime change by driving the debug binary end-to-end.

Verify a Bun runtime change

Build and drive the debug binary directly — never bun test, never import-and-call.

Build

bun bd --version   # builds ./build/debug/bun-debug and prints its version

Drive

For any JS-visible change, run the debug binary with -e and observe stdout:

bun bd -e '<repro>'   # builds, then runs; sets BUN_DEBUG_QUIET_LOGS for you

For worker/subprocess-shaped changes, spawn a subprocess (still -e) so worker teardown / event-loop-idle paths are exercised. Cross-check against node -e '<same repro>' for Node-compat changes.

Gotchas

• Prefix every bun bd with PATH="$HOME/.cargo/bin:$PATH" — Homebrew's rust formula shadows the pinned nightly, and bun bd dies with the option 'Z' is only accepted on the nightly compiler. bun bd re-runs cargo on every invocation, so this is needed for follow-up runs too, not just the first build.
• BUN_DEBUG_QUIET_LOGS=1 suppresses debug-build log spam.
• Debug builds print [cachefs]/[sys] lines to stdout; filter them before diffing output against node.
• MessagePort's .on/.off are added by requiring worker_threads — plain new MessageChannel() ports only have addEventListener until then.
• The debug+asan build is 10-100× slower than release; large-allocation stress tests can time out locally while passing in CI.