docker/cli · info · cancelledErr

containers prune has been cancelled

Error message

containers prune has been cancelled

What it means

Returned by pruneFn in cli/command/container/prune.go, the container pruner registered with `docker system prune`. When the shared pruner framework calls it with options.Confirmed=false it acts as a dry-run: it returns the confirmation message ('all stopped containers') plus this cancelledErr sentinel so the system-prune orchestrator knows this pruner needs confirmation and has not run yet. It signals control flow, not a failure.

Source

Thrown at cli/command/container/prune.go:107

			out.WriteString(id + "\n")
		}
		spaceReclaimed = res.Report.SpaceReclaimed
	}

	return spaceReclaimed, out.String(), nil
}

type cancelledErr struct{ error }

func (cancelledErr) Cancelled() {}

// pruneFn calls the Container Prune API for use in "docker system prune",
// and returns the amount of space reclaimed and a detailed output string.
func pruneFn(ctx context.Context, dockerCLI command.Cli, options pruner.PruneOptions) (uint64, string, error) {
	if !options.Confirmed {
		// Dry-run: perform validation and produce confirmation before pruning.
		confirmMsg := "all stopped containers"
		return 0, confirmMsg, cancelledErr{errors.New("containers prune has been cancelled")}
	}
	return runPrune(ctx, dockerCLI, pruneOptions{
		force:  true,
		filter: options.Filter,
	})
}

View on GitHub (pinned to e9452d6e78)

Solutions

1. Confirm the `docker system prune` prompt with 'y', or pass --force to skip confirmation entirely
2. If only stopped containers should be removed, run `docker container prune -f` directly
3. Treat this error as a cancellation sentinel (it implements a Cancelled() method), not a daemon failure — no cleanup occurred

Example fix

# before
docker system prune   # declined at prompt -> containers prune has been cancelled
# after
docker system prune --force

When it happens

Trigger: `docker system prune` invoking the container pruneFn before the user has confirmed the aggregate prompt (options.Confirmed=false); declining the `docker system prune` confirmation so the container-prune stage is reported as cancelled.

Common situations: Seen when a user declines the `docker system prune` prompt, or in non-interactive environments where the prompt cannot be answered; occasionally surfaces in logs of tooling that wraps system prune without --force.

Related errors

• container prune has been cancelled
• builder prune has been cancelled
• conflicting options: cannot specify both --network-alias and
• valid streams are STDIN, STDOUT and STDERR
• conflicting options: cannot specify both --timeout and --tim

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/f4193f26cb033b3c.json. Report an issue: GitHub.