QDatetime crash when main exited

$ cat /etc/redhat-release 
CentOS Linux release 7.6.1810 (Core) 
$ uname -a 
Linux localhost.localdomain 3.10.0-957.27.2.el7.x86_64 #1 SMP Mon Jul 29 17:46:05 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux 
$ qmake -v 
QMake version 3.0 
Using Qt version 5.7.0 in /opt/Qt5.7.0/5.7/gcc_64/lib

#include <QDateTime>

class P{
public:
    P(){}
    ~P(){
        now();
    }
    static inline void now()
   {
        QDateTime();
    }
};

int main(int argc, char *argv[])
{
     printf("start main\n");
     static P p;
     p.now();
     printf("main exit\n");
     return 0;
}