Function vwarn

util/system/err.cpp:24–40

}

void vwarn(const char* fmt, va_list args) {
    int curErrNo = errno;
    auto curErrText = LastSystemErrorText();

    Y_DEFER {
        errno = curErrNo;
    };

    Cerr << GetProgramName() << ": ";

    if (fmt) {
        Printf(Cerr, fmt, args);
        Cerr << ": ";
    }

    Cerr << curErrText << '\n';
}

void warn(const char* fmt, ...) {
    va_list args;