Create a new version of paste:

  /* "wtf.pyx":4
 * l2 = []
 * 
 * for item in l:             # <<<<<<<<<<<<<<
 *     pass
 * l2.append(item)
 */

/* __px_t_1 holds the reference to the list L at the beginning.
   PyList_CheckExact checks whether __pyx_t_1 is actually a LIST object.
   Since it is true, we bind the object __pyx_t_2 to the object __px_t_1. This is like doing a pointer reference in C/C++.
   In Python, the Garbage Collector does its job when the object reference count is zero. 
   Because we point __px_t_2 to L, the reference count must increase; hence INCREF,
   We zero __pyx_t_3 which is used as a counter later.

   Before entering the loop, we decrement the reference count for __pyx_t_1 because we use this object variable to hold something else. So the number of references made with the list object L is now 1 only, not 2.

   Enter the loop:
        since __pyx_t_4 is NULL, so the negation returns TRUE. We passed the first if (in fact we always do in this program), we use __pyx_t_1 object variable to hold the value reference of each item i in the list. That's what GET_ITEM does, and after that we increase the counter (__pyx_t_3++).

   Note before we exist the loop :

              if (PyObject_SetAttr(__pyx_m, __pyx_n_s__item, __pyx_t_1) < 0) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
              __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
  }
              __Pyx_DECREF(__pyx_t_2); __pyx_t_2 = 0;

  The first if try to set the object item with the value __pyx_t_1 points to. This is the value of the last iteration. We are saving it. At the end, we decrement the reference count for __pyx_t_1 because it is no longer used. We also decreemnt the list reference there. 

*/
      
__pyx_t_1 = __Pyx_GetName(__pyx_m, __pyx_n_s__l); if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
  __Pyx_GOTREF(__pyx_t_1);
  if (PyList_CheckExact(__pyx_t_1) || PyTuple_CheckExact(__pyx_t_1)) {
    __pyx_t_2 = __pyx_t_1; __Pyx_INCREF(__pyx_t_2); __pyx_t_3 = 0;
    __pyx_t_4 = NULL;
  } else {
    __pyx_t_3 = -1; __pyx_t_2 = PyObject_GetIter(__pyx_t_1); if (unlikely(!__pyx_t_2)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
    __Pyx_GOTREF(__pyx_t_2);
    __pyx_t_4 = Py_TYPE(__pyx_t_2)->tp_iternext;
  }
  __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
  for (;;) {
    if (!__pyx_t_4 && PyList_CheckExact(__pyx_t_2)) {
      if (__pyx_t_3 >= PyList_GET_SIZE(__pyx_t_2)) break;
      #if CYTHON_COMPILING_IN_CPYTHON
      __pyx_t_1 = PyList_GET_ITEM(__pyx_t_2, __pyx_t_3); __Pyx_INCREF(__pyx_t_1); __pyx_t_3++; if (unlikely(0 < 0)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
      #else
      __pyx_t_1 = PySequence_ITEM(__pyx_t_2, __pyx_t_3); __pyx_t_3++; if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
      #endif
    } else if (!__pyx_t_4 && PyTuple_CheckExact(__pyx_t_2)) {
      if (__pyx_t_3 >= PyTuple_GET_SIZE(__pyx_t_2)) break;
      #if CYTHON_COMPILING_IN_CPYTHON
      __pyx_t_1 = PyTuple_GET_ITEM(__pyx_t_2, __pyx_t_3); __Pyx_INCREF(__pyx_t_1); __pyx_t_3++; if (unlikely(0 < 0)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
      #else
      __pyx_t_1 = PySequence_ITEM(__pyx_t_2, __pyx_t_3); __pyx_t_3++; if (unlikely(!__pyx_t_1)) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
      #endif
    } else {
      __pyx_t_1 = __pyx_t_4(__pyx_t_2);
      if (unlikely(!__pyx_t_1)) {
        if (PyErr_Occurred()) {
          if (likely(PyErr_ExceptionMatches(PyExc_StopIteration))) PyErr_Clear();
          else {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
        }
        break;
      }
      __Pyx_GOTREF(__pyx_t_1);
    }
    if (PyObject_SetAttr(__pyx_m, __pyx_n_s__item, __pyx_t_1) < 0) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 4; __pyx_clineno = __LINE__; goto __pyx_L1_error;}
    __Pyx_DECREF(__pyx_t_1); __pyx_t_1 = 0;
  }
  __Pyx_DECREF(__pyx_t_2); __pyx_t_2 = 0;