I am unsure why below code is throwing a runtime exception when run in online compiler here. I am trying to execute a function via packaged task

#include <iostream>
#include <future>

int display(int i)
{
    std::cout << "In display";
    return i + 1;
}

int main()
{
   std::packaged_task<int(int)> pt(display);
   auto fut = pt.get_future();
   pt(5);
   std::cout << "\n PT returns " << fut.get();
   return 0;
}

The error which i am getting is

/tmp/RucY1KsPrS.o
terminate called after throwing an instance of 'std::system_error'
  what():  Unknown error -1
Aborted