What causes "Must supply channel ID" in hyperledger/fabric?

Re-run with the channel: `peer node resume -c ` (peer must be offline).

Must supply channel ID

Error message

Must supply channel ID

What it means

The `peer node resume` command resumes a previously paused channel on an offline peer and, like pause, mandates a channel ID. When channelID equals common.UndefinedParamValue (flag not supplied), RunE aborts with this error before calling kvledger.ResumeChannel.

Source

Thrown at internal/peer/node/resume.go:30

	"github.com/pkg/errors"
	"github.com/spf13/cobra"
)

func resumeCmd() *cobra.Command {
	resumeChannelCmd.ResetFlags()
	flags := resumeChannelCmd.Flags()
	flags.StringVarP(&channelID, "channelID", "c", common.UndefinedParamValue, "Channel to resume.")

	return resumeChannelCmd
}

var resumeChannelCmd = &cobra.Command{
	Use:   "resume",
	Short: "Resumes a channel on the peer.",
	Long:  `Resumes a channel on the peer. When the command is executed, the peer must be offline. When the peer starts after resume, it will receive blocks for the resumed channel.`,
	RunE: func(cmd *cobra.Command, args []string) error {
		if channelID == common.UndefinedParamValue {
			return errors.New("Must supply channel ID")
		}

		config := ledgerConfig()
		return kvledger.ResumeChannel(config.RootFSPath, channelID)
	},
}

View on GitHub (pinned to 2736b63f8f)

Solutions

Re-run with the channel: `peer node resume -c <channelID>` (peer must be offline).
Confirm the flag name `--channelID` is correctly spelled and parsed.
Ensure the scripted variable holding the channel name is non-empty before invoking the command.

Example fix

// before
peer node resume
// after
peer node resume -c mychannel

Defensive patterns

Strategy: validation

Validate before calling

if [ -z "$CHANNEL" ]; then echo "usage: peer node resume -c <channelID>" >&2; exit 1; fi
peer node resume -c "$CHANNEL"

Try / catch

if err := runResume(); err != nil && err.Error() == "Must supply channel ID" {
    return fmt.Errorf("usage: peer node resume -c <channelID>")
}

Prevention

Supply -c/--channelID on every invocation.
Validate channel name non-empty in maintenance scripts.
Run pause/resume pairs with identical channel variables to avoid mismatches.

When it happens

Trigger: Running `peer node resume` without --channelID / -c.

Common situations: Omitting -c after maintenance; flag typo; passing an empty variable in an automation script during channel maintenance windows.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/8d089d7eb77ab9c3. Report an issue: GitHub.