the required parameter 'channelID' is empty. Rerun the comma

Error message

the required parameter 'channelID' is empty. Rerun the command with -c flag

What it means

The peer snapshot cancelrequest command validates that the mandatory -c/--channelID flag was supplied before submitting a CancelSnapshotRequest to the peer. When the package-level channelID variable is empty, this error aborts the command with an instruction to rerun with -c.

Source

Thrown at internal/peer/snapshot/cancelrequest.go:84

		BlockNumber:     blockNumber,
	}
	signedRequest, err := signSnapshotRequest(cl.signer, request)
	if err != nil {
		return err
	}

	_, err = cl.snapshotClient.Cancel(context.Background(), signedRequest)
	if err != nil {
		return errors.WithMessage(err, "failed to cancel the request")
	}

	fmt.Fprint(cl.writer, "Snapshot request cancelled successfully\n")
	return nil
}

func validateCancelRequest() error {
	if channelID == "" {
		return errors.New("the required parameter 'channelID' is empty. Rerun the command with -c flag")
	}
	if blockNumber == 0 {
		return errors.New("the required parameter 'blockNumber' is empty or set to 0. Rerun the command with -b flag")
	}
	return nil
}

View on GitHub (pinned to 2736b63f8f)

Solutions

Rerun with the channel flag: peer snapshot cancelrequest -c <channelID> -b <blockNumber>.
In scripts, guard with a check like [ -n "$CHANNEL" ] before invoking the command.
Verify the flag binding: use the full --channelID form if parsing issues are suspected.

Example fix

// before
peer snapshot cancelrequest -b 1500
// after
peer snapshot cancelrequest -c mychannel -b 1500

Defensive patterns

Strategy: validation

Validate before calling

if [ -z "$CHANNEL" ]; then echo "usage: peer snapshot cancelrequest -c <channelID> -b <blockNumber>"; exit 1; fi
peer snapshot cancelrequest -c "$CHANNEL" -b "$BLOCK"

Prevention

Always pass -c and -b together for snapshot cancelrequest
Validate env vars in wrapper scripts
Check --help output before scripting snapshot subcommands

When it happens

Trigger: Running 'peer snapshot cancelrequest' without the -c/--channelID flag, or with -c "" so the flag binding leaves channelID empty.

Common situations: Scripted snapshot cancellation built from templates where the channel variable failed to expand; forgetting the flag because it is required only for snapshot subcommands; copy-pasting an example command that omitted -c.

Understand the failure class

Background: "--flag is required" and "must specify" CLI errors: how missing-required-flag validation works and how to fix it — this error's family across 20 libraries.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/aec938ed4d2be00f. Report an issue: GitHub.