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

self = <rpython.jit.metainterp.test.test_fficall.TestFfiCall object at 0x7f52a3f4ab10>

    def test_returns_none(self):
        self._run([types.signed] * 2, types.void, [456, 789], None,
>                 expected_call_release_gil_i=0, expected_call_release_gil_n=1)

jit/metainterp/test/test_fficall.py:225: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
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 0x7f52a3f51250>
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

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

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