std::string LinuxLocalDerivationGoal::rewriteResolvConf(std::string fromHost)
{
    if (!runPasta) {
        return fromHost;
    }

    static constexpr auto flags = std::regex::ECMAScript | std::regex::multiline;
    static auto lineRegex = regex::parse("^nameserver\\s.*$", flags);
    static auto v4Regex = regex::parse("^nameserver\\s+\\d{1,3}\\.", flags);
    static auto v6Regex = regex::parse("^nameserver.*:", flags);
    std::string nsInSandbox = "\n";
    if (std::regex_search(fromHost, v4Regex)) {
        nsInSandbox += fmt("nameserver %s\n", PASTA_HOST_IPV4);
    }
    if (std::regex_search(fromHost, v6Regex)) {
        nsInSandbox += fmt("nameserver %s\n", PASTA_HOST_IPV6);
    }
    return std::regex_replace(fromHost, lineRegex, "") + nsInSandbox;
}