Issues
MIR-658

Build logs missing buildkit output and onbuild command output

Done public
Capture BuildKit output in build logs

Problem

When running miren logs --build <version>, the output only shows the detection phase:

U 2026-02-04 09:48:50: [build] [detect] package.json: Found package.json
U 2026-02-04 09:48:50: [build] [detect] bun.lock: Found bun.lock (Bun runtime)
U 2026-02-04 09:48:50: [build] [detect] start: bun start script detected
U 2026-02-04 09:48:50: [build] version=mirendev-vCXoHurY9JwBuyVjNqfE9Y artifact=mirendev-aCXoHXsECKx17qrLHp6tqB status=deployed

Expected

Build logs should include:

  1. Buildkit layer output - which layers were cached vs rebuilt
  2. Onbuild command output - the full output of bun run build (in this case, astro build output including font loading, static page generation, OG image generation, etc.)

During miren deploy, we see this output in the terminal, but it's not captured in miren logs --build.

Why it matters

When debugging build issues (like cache invalidation problems), we need to see:

  • Which build steps ran vs were cached
  • The actual output of build commands to diagnose failures