def test_command_copy_failing(self, t, read_tftp):
        read_tftp.side_effect = Exception("Stuff")

        enable(t)

        t.write("copy tftp://1.2.3.4/my-file system:/running-config")
        t.read("Destination filename [running-config]? ")
        t.write("gneh")
        t.readln("Accessing tftp://1.2.3.4/my-file...")
        t.readln("Error opening tftp://1.2.3.4/my-file (Timed out)")
        t.read("my_switch#")

        read_tftp.assert_called_with("1.2.3.4", "my-file")