CircleCI "Too long with no output (exceeded 10m): context deadline"

By Kaveh Alemi·Latchkey

CircleCI cancels a step that goes 10 minutes without writing to stdout/stderr. It is a safety timeout against hung jobs - the step may still be working, just silently.

What this error means

A long, quiet step (a big download, a slow test, a buffered build) is cut off with "Too long with no output (exceeded 10m0s): context deadline exceeded", even while making progress.

Too long with no output (exceeded 10m0s): context deadline exceeded

Common causes

A genuinely slow but silent step

A large install, dataset download, or compile runs longer than 10 minutes without printing, so the default no_output_timeout cancels it.

Buffered output that never flushes

A tool buffers logs and emits nothing until the end, so CircleCI sees no output and assumes a hang.

A real hang or deadlock

The step is actually stuck - a lock, a prompt, or a network call that never returns - and the timeout correctly fires.

How to fix it

Raise no_output_timeout for slow steps

- run:
    name: Integration tests
    command: ./run-slow-tests.sh
    no_output_timeout: 30m

Emit progress or unbuffer output

1. Enable the tool's verbose/progress output so it prints periodically.
2. Wrap chatty-but-buffered commands with stdbuf -oL or unbuffer.
3. If it is a true hang, fix the underlying lock or network wait.

How to prevent it

• Set a realistic no_output_timeout on known-slow steps.
• Keep long steps emitting progress so the timeout never trips.
• Investigate repeated timeouts as possible deadlocks.

Frequently asked questions

Related guides

References

• GitHub Actions documentation