IndexError: tuple index out of range

Found in sympy v1.0 test cases.

Traceback (most recent call last):
  File "/tmp/tmpz56qw_4w/sympy__sympy__1.0/sympy/utilities/runtests.py", line 1130, in wrapper
    test_func()
  File "/tmp/tmpz56qw_4w/sympy__sympy__1.0/sympy/functions/special/tests/test_zeta_functions.py", line 95, in test_derivatives
    assert zeta(x, a).diff(x) == Derivative(zeta(x, a), x)
  File "/home/db/dev/applandinc/appmap-python/_appmap/wrapt/wrappers.py", line 712, in __call__
    return self._self_wrapper(self.__wrapped__, self._self_instance,
  File "/home/db/dev/applandinc/appmap-python/_appmap/instrument.py", line 129, in instrumented_fn
    return call_instrumented(f, instance, args, kwargs)
  File "/home/db/dev/applandinc/appmap-python/_appmap/instrument.py", line 92, in call_instrumented
    ret = f.fn(*args, **kwargs)
  File "/tmp/tmpz56qw_4w/sympy__sympy__1.0/sympy/core/expr.py", line 2949, in diff
    return Derivative(self, *new_symbols, **assumptions)
  File "/tmp/tmpz56qw_4w/sympy__sympy__1.0/sympy/core/function.py", line 1187, in __new__
    obj = expr._eval_derivative(v)
  File "/home/db/dev/applandinc/appmap-python/_appmap/wrapt/wrappers.py", line 712, in __call__
    return self._self_wrapper(self.__wrapped__, self._self_instance,
  File "/home/db/dev/applandinc/appmap-python/_appmap/instrument.py", line 129, in instrumented_fn
    return call_instrumented(f, instance, args, kwargs)
  File "/home/db/dev/applandinc/appmap-python/_appmap/instrument.py", line 92, in call_instrumented
    ret = f.fn(*args, **kwargs)
  File "/tmp/tmpz56qw_4w/sympy__sympy__1.0/sympy/core/function.py", line 559, in _eval_derivative
    df = self.fdiff(i)
  File "/home/db/dev/applandinc/appmap-python/_appmap/wrapt/wrappers.py", line 712, in __call__
    return self._self_wrapper(self.__wrapped__, self._self_instance,
  File "/home/db/dev/applandinc/appmap-python/_appmap/instrument.py", line 129, in instrumented_fn
    return call_instrumented(f, instance, args, kwargs)
  File "/home/db/dev/applandinc/appmap-python/_appmap/instrument.py", line 103, in call_instrumented
    event.ExceptionEvent(
  File "/home/db/dev/applandinc/appmap-python/_appmap/event.py", line 509, in __init__
    {"class": fqname(class_), "message": str(exc), "object_id": id(exc)}
  File "/tmp/tmpz56qw_4w/sympy__sympy__1.0/sympy/core/function.py", line 94, in __str__
    (self.args[1], self.args[0]))
IndexError: tuple index out of range

从 _appmap/event.py 第 509 行附近以及 _appmap/instrument.py 中的异常处理路径开始。运行 SymPy v1.0 的 test_zeta_functions.py 中的 test_derivatives 用例来重现故障。完成的标准是：处理该异常时不再发生报告的 IndexError，并且测试完成。