jit/metainterp/test/test_fficall.py::TestFfiCall::()::test_calldescrof_dynamic_returning_none

self = <rpython.jit.metainterp.test.test_fficall.TestFfiCall object at 0x7f52a3e2e410>

    def test_calldescrof_dynamic_returning_none(self):
        from rpython.jit.backend.llgraph.runner import LLGraphCPU
        old = LLGraphCPU.calldescrof_dynamic
        try:
            LLGraphCPU.calldescrof_dynamic = lambda *args: None
            self.test_simple_call_float(expected_call_release_gil=0,
>                                       expected_call_may_force_f=1)

jit/metainterp/test/test_fficall.py:386: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
jit/metainterp/test/test_fficall.py:188: in test_simple_call_float
    self._run([types.double] * 2, types.double, [45.6, 78.9], -4.2, **kwds)
jit/metainterp/test/test_fficall.py:142: in _run
    with FakeFFI(fake_call_impl_any):
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <rpython.jit.metainterp.test.test_fficall.FakeFFI object at 0x7f52a3e2ec10>
args = ()

    def __enter__(self, *args):
>       self.monkey.setattr(jit_libffi, 'jit_ffi_call_impl_any', self.fake_call_impl_any)
E       AttributeError: 'generator' object has no attribute 'setattr'

jit/metainterp/test/test_fficall.py:40: AttributeError
 (somefailed=True in jit/metainterp/test/test_fficall.py)

builder: rpython-linux-x86-64 build #887

test: jit/metainterp/test/test_fficall/py/TestFfiCall/()/test_calldescrof_dynamic_returning_none