hashicorp/terraform · error

failed to unmarshal JSON data into LockInfo struct: %w

Error message

failed to unmarshal JSON data into LockInfo struct: %w

What it means

Raised in getLockInfo when the lock file bytes were read successfully but json.Unmarshal into statemgr.LockInfo failed. The lock file object exists and is non-empty, but its content is not valid JSON or does not fit the LockInfo schema, so the lock holder identity (ID, Operation, Who, etc.) cannot be recovered.

Source

Thrown at internal/backend/remote-state/oci/client.go:320

		NamespaceName: common.String(c.namespace),
		ObjectName:    common.String(c.lockFilePath),
		BucketName:    common.String(c.bucketName),
		RequestMetadata: common.RequestMetadata{
			RetryPolicy: getDefaultRetryPolicy(),
		},
	}

	getResponse, err := c.objectStorageClient.GetObject(ctx, getRequest)
	if err != nil {
		return nil, "", fmt.Errorf("failed to get existing lock file: %w", err)
	}
	lockByteData, err := io.ReadAll(getResponse.Content)
	if err != nil {
		return nil, *getResponse.ETag, fmt.Errorf("failed to read existing lock file content: %w", err)
	}
	lockInfo := &statemgr.LockInfo{}
	if err := json.Unmarshal(lockByteData, lockInfo); err != nil {
		return lockInfo, "", fmt.Errorf("failed to unmarshal JSON data into LockInfo struct: %w", err)
	}
	return lockInfo, *getResponse.ETag, nil
}
func (c *RemoteClient) Unlock(id string) error {
	ctx := context.TODO()
	logger := logWithOperation("unlock-state-file").Named(c.lockFilePath)
	logger.Info("unlocking remote state")
	lockInfo, etag, err := c.getLockInfo(ctx)

	if err != nil {
		return fmt.Errorf("Failed to retrieve lock information from OCI Object Storage: %w", err)
	}
	// Verify that the provided lock ID matches the lock ID of the retrieved lock file.
	if lockInfo.ID != id {
		return &statemgr.LockError{
			Info: lockInfo,
			Err:  fmt.Errorf("lock ID '%s' does not match the existing lock ID '%s'", id, lockInfo.ID),
		}

View on GitHub (pinned to c9def3e214)

Solutions

1. Download the lock file (oci os object get) and inspect its bytes; if it is an error page or corrupt, delete it and re-acquire the lock.
2. Confirm all teams/CI use a compatible Terraform version that shares the LockInfo schema.
3. If the content is a valid-but-different JSON, map the fields manually or migrate to the current schema before deleting the lock.
4. After cleaning up, run 'terraform force-unlock <id>' only if you are certain no real lock is held.

// Validate the bytes are JSON before unmarshalling into LockInfo:
if !json.Valid(lockByteData) {
    return lockInfo, "", fmt.Errorf("lock file is not valid JSON")
}
if err := json.Unmarshal(lockByteData, lockInfo); err != nil { ... }

var syntaxErr *json.SyntaxError
if errors.As(err, &syntaxErr) { /* malformed JSON */ }
var typeErr *json.UnmarshalTypeError
if errors.As(err, &typeErr) { /* schema mismatch */ }

if err := json.Unmarshal(lockByteData, lockInfo); err != nil {
    return lockInfo, "", fmt.Errorf("failed to unmarshal JSON data into LockInfo struct: %w", err)
}

When it happens

Trigger: json.Unmarshal(lockByteData, lockInfo) at client.go:319 fails: the lock file contains malformed JSON, is a different format (e.g. an HTML error page cached by a proxy), or has extra/missing fields incompatible with the LockInfo struct in this Terraform version.

Common situations: A lock file written by a different/newer Terraform whose LockInfo schema differs; manual corruption of the lock object; a transparent proxy returning an HTML error that got stored/cached at the lock key; partial write of the lock file.

Related errors

• object %q is empty
• uploadSinglePartObject: data is empty
• failed to read existing lock file content: %w
• Failed to retrieve lock information from OCI Object Storage:
• lock ID '%s' does not match the existing lock ID '%s'

AI-assisted analysis of hashicorp/terraform@c9def3e214 (2026-08-07). Data as JSON: /api/errors/3dd15366d6581510. Report an issue: GitHub.