On 3 May 2017 at 17:04, Papa wrote: > Yes, absolutely right. That's what I thought as well. > Now, who should look at this problem, MinGW64 or Gnu, who should I contact > to report this bug? MinGW's setlocale has nothing to do with GCC, it's provided by MinGW. What happens if you use a non-statically allocated char* directly, without involving std::string? void jme::Locale::setGlobalLocale(const std::string&){ char arr[] = ""; std::setlocale(LC_ALL, arr ); } Or maybe more likely to fail immediately: void jme::Locale::setGlobalLocale(const std::string&){ char* p = new char[1](); std::setlocale(LC_ALL, p ); delete[] p; }