[BUG] Segmentation fault

I’m writing a bridge for ruby to python.
50 static PyObject *ruby_require(PyObject *self, PyObject *args){
51 static const char *module = NULL;
52 if (!PyArg_ParseTuple(args, “s”, &module)){
53 return NULL;
54 }
55 safe_require(module);
56 Py_INCREF(Py_None);
57 return Py_None;
58 }
Function safe_require just called rb_require.

When requiring my own ruby scripts under current path could success).
but when I want to require standard libraries like ‘base64’ and etc.
I got this error message:

/usr/lib/ruby/1.8/base64.rb:58: [BUG] Segmentation fault
ruby 1.8.7 (2009-06-12 patchlevel 174) [i486-linux]

Maybe who knows what’s wrong?