Docker exit code 137 (OOM) during build in CI

Exit 137 is 128 + 9, meaning SIGKILL. During a build it is almost always the out-of-memory killer terminating a RUN that exceeded available memory.

What this error means

A RUN step (often a bundler, compile, or test) exits with code 137 and frequently the single word Killed. There is no stack trace because SIGKILL cannot be caught.

docker

#12 137.4 Killed
ERROR: process "/bin/sh -c npm run build" did not complete successfully: exit code: 137

Common causes

Build exceeded memory

Webpack/bundler builds, large compiles, and heavy test suites can spike past the runner memory ceiling, triggering the cgroup OOM killer.

Container memory limit too low

An explicit --memory or compose memory limit smaller than the build needs causes the same kill.

How to fix it

Give the build more memory

Run on a larger runner, or raise/remove an explicit container memory limit.
For Node, cap the heap below the limit with NODE_OPTIONS.

Dockerfile

ENV NODE_OPTIONS=--max-old-space-size=4096

Reduce peak memory

Lower build parallelism (make -j2, jest --maxWorkers=2).
Split a monolithic build step into smaller ones.

How to prevent it

Right-size runners for memory-heavy builds and set language heap limits relative to runner memory. Latchkey managed runners auto-retry a transient OOM and can place the job on a larger runner, so an occasional memory spike does not hard-fail the pipeline.