help for example with Condition

[Mikhail]

I wrote simple example to learn how the work Conditions.
But program closed with signal, what's wrong?

import std.stdio;
import core.thread;
import core.sync.condition;
import core.sync.mutex;


Condition cond;
Mutex mutex;

void threadFunction()
{
     writeln("This is running in a separate thread.");
     Duration d = dur!"msecs"(100);
     writeln(d);
     cond.wait(d);
}

void main() {
     mutex = new Mutex();
     cond = new Condition(mutex);

     auto t = new Thread(&threadFunction);
     t.start();

     t.join();
     writeln("Main thread finished.");
}