a collection specified chaincode %s but it wasn't specified

Error message

a collection specified chaincode %s but it wasn't specified with a chaincode flag

What it means

parseInput validates that every chaincode named in a --collection flag (Collections map) is also present in the chaincode selection. Collections only exist within a chaincode's definition, so referencing a collection for a chaincode that was never selected gives discovery nothing to resolve against and the request is rejected.

Source

Thrown at discovery/cmd/endorsers.go:187

	if ec.Collections == nil {
		ec.Collections = &emptyCollections
	}

	res := make(map[string][]string)

	for _, cc := range *ec.Chaincodes {
		res[cc] = nil
	}

	for _, cc := range *ec.NoPrivReads {
		if !ec.existsInChaincodes(cc) {
			return nil, errors.Errorf("chaincode %s is specified as not containing private data reads but should be explicitly defined via a chaincode flag", cc)
		}
	}

	for cc, collections := range *ec.Collections {
		if !ec.existsInChaincodes(cc) {
			return nil, errors.Errorf("a collection specified chaincode %s but it wasn't specified with a chaincode flag", cc)
		}
		res[cc] = strings.Split(collections, ",")
	}

	return res, nil
}

func parseEndorsementDescriptors(descriptors []*discovery.EndorsementDescriptor) []endorsermentDescriptor {
	var res []endorsermentDescriptor
	for _, desc := range descriptors {
		endorsersByGroups := make(map[string][]endorser)
		for grp, endorsers := range desc.EndorsersByGroups {
			for _, p := range endorsers.Peers {
				endorsersByGroups[grp] = append(endorsersByGroups[grp], endorserFromRaw(p))
			}
		}
		res = append(res, endorsermentDescriptor{
			Chaincode:         desc.Chaincode,

View on GitHub (pinned to 2736b63f8f)

Solutions

Pass --chaincode CC for the chaincode that owns the collection
Correct the chaincode name in the --collection flag to match an existing --chaincode value
Remove the --collection flag if the chaincode is not being queried

Example fix

// before
discover endorsers --server peer:7051 --collection mycc:coll1

// after
discover endorsers --server peer:7051 --chaincode mycc --collection mycc:coll1

Defensive patterns

Strategy: validation

Validate before calling

const chaincodes = flags.chaincode || [];
const collCCs = (flags.collection || []).map(c => c.split(':')[0]);
const missing = collCCs.filter(cc => !chaincodes.includes(cc));
if (missing.length > 0) {
  throw new Error(`collections reference chaincodes not in --chaincode: ${missing.join(',')}`);
}

Type guard

function allCollectionsBelongToChaincodes(chaincodes, collections) {
  return collections.every(c => chaincodes.includes(c.split(':')[0]));
}

Try / catch

try {
  await discoverEndorsers(args);
} catch (e) {
  if (/wasn't specified with a chaincode flag/.test(e.message)) {
    const cc = e.message.match(/chaincode (\S+)/)?.[1];
    args.chaincode.push(cc); // or abort
  }
}

Prevention

Always pair --collection with a --chaincode flag for the same chaincode
Derive collection flags from the chaincode definition's collection config
Validate the collection prefix matches a chaincode before running

When it happens

Trigger: Running `discover endorsers --collection CC:coll1` without also passing `--chaincode CC`, or the chaincode name before the colon in --collection not matching any --chaincode flag value.

Common situations: Forgetting the --chaincode flag when only interested in a collection; renaming a chaincode and updating --collection but not --chaincode; shell scripts building flags where the collection list references old chaincode names.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/5933b9a73545daeb. Report an issue: GitHub.