writeln() assertion failed in hybrid x64

[Szymon Gatner via Digitalmars-d-learn]

Hey,

I am trying to build hybrid (C++, D) application (more here: 
http://forum.dlang.org/thread/ugkpqprobonorbdun...@forum.dlang.org) 
but I am now getting assertion failure from within writeln(). 
writeln() is called from a D function that has C++ linkage:

D definition:

extern (C++) void printSomething()
{
  writeln("hello from D");
}


usage from C++:

extern "C++" void printSomething();

int main()
{
  DRuntime druntime; // rt_init(), rt_term()
  printSomething();
}

this causes run-time assertion in fprintf() called from within 
writeln():

int __cdecl fprintf (
        FILE *str,
        const char *format,
        ...
        )
/*
 * 'F'ile (stream) 'PRINT', 'F'ormatted
 */
{
    va_list(arglist);
    FILE *stream;
    int buffing;
    int retval=0;

    _VALIDATE_RETURN( (str != NULL), EINVAL, -1); <=== assetion 
here

[...]
}

meaning that str arg passed is null. writelns()'s call site:

        enforce(fprintf(.stdout._p.handle, "%.*s\n",
                        cast(int) args[0].length, args[0].ptr) >= 
0);

so for some reason .stdout._p.handle is null.