hyperledger/fabric · error

error marshalling msp role: %s

Error message

error marshalling msp role: %s

What it means

This error is returned by the internal secondPass function of the policy DSL parser (common/policydsl/policyparser.go:198) when the protobuf marshalling of an MSPRole message fails. The parser has already matched a valid 'ORG.ROLE' principal string and resolved the role to an MSPRole_MSPRoleType, but the call to proto.Marshal(&mb.MSPRole{...}) returned an error. In practice this is extremely rare because MSPRole is a simple proto message whose marshal cannot fail with valid input.

Source

Thrown at common/policydsl/policyparser.go:198

			switch subm[0][3] {
			case RoleMember:
				r = mb.MSPRole_MEMBER
			case RoleAdmin:
				r = mb.MSPRole_ADMIN
			case RoleClient:
				r = mb.MSPRole_CLIENT
			case RolePeer:
				r = mb.MSPRole_PEER
			case RoleOrderer:
				r = mb.MSPRole_ORDERER
			default:
				return nil, fmt.Errorf("error parsing role %s", t)
			}

			/* build the principal we've been told */
			mspRole, err := proto.Marshal(&mb.MSPRole{MspIdentifier: subm[0][1], Role: r})
			if err != nil {
				return nil, fmt.Errorf("error marshalling msp role: %s", err)
			}

			p := &mb.MSPPrincipal{
				PrincipalClassification: mb.MSPPrincipal_ROLE,
				Principal:               mspRole,
			}
			ctx.principals = append(ctx.principals, p)

			/* create a SignaturePolicy that requires a signature from
			   the principal we've just built*/
			dapolicy := SignedBy(int32(ctx.IDNum))
			policies = append(policies, dapolicy)

			/* increment the identity counter. Note that this is
			   suboptimal as we are not reusing identities. We
			   can deduplicate them easily and make this puppy
			   smaller. For now it's fine though */
			// TODO: deduplicate principals

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Verify the project imports a consistent, compatible set of github.com/hyperledger/fabric-protos-go-apiv2 and google.golang.org/protobuf versions (run go mod tidy and go mod verify)
2. Inspect the wrapped error text after 'error marshalling msp role: ' to identify the actual proto failure (e.g. nil pointer, unknown field)
3. Upgrade fabric-protos-go-apiv2 and the protobuf runtime to versions matching your fabric release
4. If reproducible, test proto.Marshal directly on an MSPRole value to isolate the proto runtime issue
5. Rebuild with a clean module cache (go clean -modcache && go mod download) to rule out corrupted vendor/module state

Example fix

// before (dependency mismatch causing marshal failure)
require github.com/hyperledger/fabric-protos-go-apiv2 v0.0.0-20220101...
// after (pin a version compatible with your fabric release)
go get github.com/hyperledger/fabric-protos-go-apiv2@latest && go mod tidy

import "google.golang.org/protobuf/proto"
import mb "github.com/hyperledger/fabric-protos-go-apiv2/msp"

func canMarshalMSPRole(mspID string) error {
	_, err := proto.Marshal(&mb.MSPRole{MspIdentifier: mspID, Role: mb.MSPRole_MEMBER})
	return err
}
// run at startup: if err := canMarshalMSPRole("Org1MSP"); err != nil { /* fix proto deps */ }

_, err := policydsl.FromString(policy)
if err != nil && strings.Contains(err.Error(), "error marshalling msp role") {
	// proto runtime/dependency problem: verify fabric-protos + protobuf versions
	return fmt.Errorf("policy %q: proto runtime issue: %w", policy, err)
}

When it happens

Trigger: Calling policydsl.FromString with a principal like 'Org1.member' when the underlying proto.Marshal of MSPRole{MspIdentifier, Role} fails - essentially only with corrupt protobuf library state, nil registry issues, or an incompatible/older protos dependency where the MspIdentifier field cannot be serialized.

Common situations: Broken or mismatched fabric-protos dependency versions; a vendored or replaced protobuf runtime that cannot marshal MSPRole; none in normal usage - developers essentially never hit this in the field.

Related errors

• marshalling failed
• malformed org definition for org: %s
• error encode input
• message of type %s unknown
• error marshaling: proto: Marshal called with nil

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/fd087af1703a8cc1. Report an issue: GitHub.