drake: Workaround "Assertion '!PyErr_Occurred()'" for dtype=object (#52)

Author: EricCousineau-TRI

include/pybind11/detail/class.h

@@ -157,6 +157,12 @@ extern "C" inline int pybind11_meta_setattro(PyObject* obj, PyObject* name, PyOb
  * to do a special case bypass for PyInstanceMethod_Types.
  */
 extern "C" inline PyObject *pybind11_meta_getattro(PyObject *obj, PyObject *name) {
+    // Workaround! See:
+    // https://github.com/RobotLocomotion/drake/issues/14740
+    // https://github.com/pybind/pybind11/pull/2685
+    if (PyErr_Occurred()) {
+        PyErr_Clear();
+    }
     PyObject *descr = _PyType_Lookup((PyTypeObject *) obj, name);
     if (descr && PyInstanceMethod_Check(descr)) {
         Py_INCREF(descr);