kopia/kopia · error

error parsing storage config for bucket

Error message

error parsing storage config for bucket %q

What it means

Wrapped error from StorageConfig.Load during newStorageWithCredentials: after fetching the storage-config blob (ConfigName) from the bucket, its JSON contents could not be decoded. The parse error is in errors.Cause.

Solutions

1. Inspect and fix the JSON in the config blob at key ConfigName in the bucket
2. Delete/recreate the repository config blob if corrupted (will require re-connect)
3. Ensure all clients use a compatible kopia version
4. Check for proxy/upload truncation that cut off the JSON

var probe map[string]any
if err := json.Unmarshal(configBlobBytes, &probe); err != nil {
    return fmt.Errorf("repository config blob is not valid JSON: %w", err)
}

func isLikelyJSON(b []byte) bool {
    t := bytes.TrimSpace(b)
    return len(t) > 0 && (t[0] == '{' || t[0] == '[')
}

store, err := s3.New(ctx, &opt)
if err != nil && strings.Contains(err.Error(), "error parsing storage config") {
    // inspect/repair the config blob or re-initialize the repository
    return fmt.Errorf("corrupt repository config: %w", err)
}

When it happens

Trigger: The kopia.repository/config blob in the S3 bucket exists but contains invalid or truncated JSON — e.g. written by a different/older format, corrupted upload, or manually edited.

Common situations: Bucket previously used by another tool; partial upload of the config blob; hand-editing of stored config; version mismatch between client formats.

Understand the failure class

Background: JSON parse error: "Unexpected token" / "not valid JSON" / "failed to parse" — what JSON parsers are really complaining about — this error's family across 45 libraries.

Related errors

• error parsing JSON
• error parsing JSON
• error retrieving storage config from bucket
• error unmarshaling connection info JSON
• errors indenting JSON

AI-assisted analysis of kopia/kopia@82495e54b5 (2026-09-07). Data as JSON: /api/errors/2b60dca73ad780f2. Report an issue: GitHub.

Appendix: source

Thrown at repo/blob/s3/s3_storage.go:465

		return nil, err
	}

	cli, err := minio.New(opt.Endpoint, minioOpts)
	if err != nil {
		return nil, errors.Wrap(err, "unable to create client")
	}

	s := s3Storage{
		Options:       *opt,
		cli:           cli,
		storageConfig: &StorageConfig{},
	}

	var scOutput gather.WriteBuffer

	if getBlobErr := s.GetBlob(ctx, ConfigName, 0, -1, &scOutput); getBlobErr == nil {
		if scErr := s.storageConfig.Load(scOutput.Bytes().Reader()); scErr != nil {
			return nil, errors.Wrapf(scErr, "error parsing storage config for bucket %q", opt.BucketName)
		}
	} else if !errors.Is(getBlobErr, blob.ErrBlobNotFound) {
		return nil, errors.Wrapf(getBlobErr, "error retrieving storage config from bucket %q", opt.BucketName)
	}

	return &s, nil
}

func init() {
	blob.AddSupportedStorage(s3storageType, Options{}, New)
}

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