Progressive Hints

Hint 1 (after 5 min)

"exec format error" means the binary cannot be executed on this platform. Compare docker inspect showing Architecture: arm64 with uname -m showing x86_64. The image was built for the wrong CPU architecture.

Hint 2 (after 10 min)

Look at the CI runner log line: it says "built amd64/linux image" but the runner name is gitlab-runner-arm64-02. The registry log confirms the pushed manifest has arch=arm64. The CI runner is an ARM machine that built a native image but labeled it incorrectly — or the build did not cross-compile.

Hint 3 (after 15 min)

This is a PDF rendering service (Node.js) that processes a queue of pending jobs. The Dockerfile builds a Node app into /app/render. The CI pipeline ran on an ARM64 GitLab runner, which built a native ARM64 image. That image was pushed to the registry and deployed to an x86_64 Docker host. The x86 kernel cannot execute the ARM64 binary, producing "exec format error." There are 1,847 queued PDF jobs waiting — the service has been down for over 2 hours.