std::cin in Fiasco/L4Re (with 'make qemu')

How do I use std::cin in Fiasco/L4Re?

The software compiles and links fine, only during
execution (with 'make qemu'), this crashes it:

Global_Scheduler::Global_Scheduler (bool read_from_file) :
  period_left(0),
  number_of_schedulers(0) {
  if (not read_from_file) {
    std::cout << "Global scheduler period: ";
    std::cin >> period;
    // ...

There is no error, but there is no halt to execution
(to wait for input), and the value "read" (to period)
is inconsistent.

-- 
underground experts united:
http://user.it.uu.se/~embe8573