tests: fix test_repr_traceback_with_invalid_cwd

Author: blueyed

testing/code/test_excinfo.py

@@ -775,14 +775,20 @@ def entry():
         )
         excinfo = pytest.raises(ValueError, mod.entry)
 
-        p = FormattedExcinfo()
+        p = FormattedExcinfo(abspath=False)
+
+        raised = 0
 
         def raiseos():
-            raise OSError(2)
+            nonlocal raised
+            raised += 1
+            raise OSError(2, "custom_oserror")
 
         monkeypatch.setattr(os, "getcwd", raiseos)
         assert p._makepath(__file__) == __file__
+        assert raised == 1
         p.repr_traceback(excinfo)
+        assert raised >= 3  # typically 3, 5 on py38-windows
 
     def test_repr_excinfo_addouterr(self, importasmod, tw_mock):
         mod = importasmod(