docker/cli · warning · cancelledErr

system prune has been cancelled

Error message

system prune has been cancelled

What it means

Returned by runPrune (cli/command/system/prune.go:87) wrapped in a cancelledErr when the user declines the confirmation prompt (and --force was not set). It is a controlled cancellation — cancelledErr implements the Cancelled() marker method — not a system failure; distinguish it from real prune errors.

Solutions

1. Answer 'y' to confirm at the prompt.
2. Use `--force`/`-f` to skip the prompt in scripts: `docker system prune -f`.
3. Detect cancellation programmatically by checking for the `Cancelled()` method on the returned error.

Example fix

// before
docker system prune   # -> types 'n' -> system prune has been cancelled

// after (scripts)
docker system prune --force
# or programmatically detect cancellation:
// var c interface{ Cancelled() }
// if errors.As(err, &c) { /* user cancelled, not a failure */ }

// Detect a user-initiated cancellation vs a real prune failure.
func isCancelled(err error) bool {
	var c interface{ Cancelled() }
	return errors.As(err, &c)
}

err := runPrune(ctx, dockerCli, options)
if err != nil {
	var c interface{ Cancelled() }
	if errors.As(err, &c) {
		// user declined the prompt — not a failure; exit 0 or log and continue
		return nil
	}
	return err
}

When it happens

Trigger: Running `docker system prune` interactively and answering 'n' (or anything non-affirmative) at the 'Are you sure you want to continue?' prompt; a non-interactive invocation where the input stream yields no confirmation.

Common situations: Cautious operator declines; a script forgot `--force` and the TTY/piped input doesn't confirm; CI harness that expects pruning but didn't pass -f.

Related errors

• network prune has been cancelled
• builder prune has been cancelled
• container prune has been cancelled
• containers prune has been cancelled
• every ip-range or gateway must have a corresponding subnet

AI-assisted analysis of docker/cli@4f84911bfe (2026-08-07). Data as JSON: /api/errors/b095329fb0aa9355. Report an issue: GitHub.

Appendix: source

Thrown at cli/command/system/prune.go:87

Are you sure you want to continue?`

func runPrune(ctx context.Context, dockerCli command.Cli, options pruneOptions) error {
	// prune requires either force, or a user to confirm after prompting.
	confirmed := options.force

	// Validate the given options for each pruner and construct a confirmation-message.
	confirmationMessage, err := dryRun(ctx, dockerCli, options)
	if err != nil {
		return err
	}
	if !confirmed {
		var err error
		confirmed, err = prompt.Confirm(ctx, dockerCli.In(), dockerCli.Out(), confirmationMessage)
		if err != nil {
			return err
		}
		if !confirmed {
			return cancelledErr{errors.New("system prune has been cancelled")}
		}
	}

	var spaceReclaimed uint64
	for contentType, pruneFn := range pruner.List() {
		switch contentType {
		case pruner.TypeVolume:
			if !options.pruneVolumes {
				continue
			}
		case pruner.TypeContainer, pruner.TypeNetwork, pruner.TypeImage, pruner.TypeBuildCache:
			// no special handling; keeping the "exhaustive" linter happy.
		default:
			// other pruners; no special handling; keeping the "exhaustive" linter happy.
		}

		spc, output, err := pruneFn(ctx, dockerCli, pruner.PruneOptions{
			Confirmed: confirmed,

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