// versions.
		//
		// Fall back to this resolution scheme only if the GOPROXY setting prohibits
		// us from resolving upstream tags.
		if cfg.GOPROXY == "off" {
			if file, info, err := readDiskStatByHash(ctx, path, rev); err == nil {
				return file, info, nil
			}
		}
		return file, nil, err
	}
	info = new(RevInfo)
	if err := json.Unmarshal(data, info); err != nil {
		return file, nil, errNotCached