Shall we need to run the unit tests with CPU mode on CI

[Yancey1989]

I found the unit test related selected_rows run failed with cmake flag is WITH_GPU=OFF, and @luotao1 also reproduce this situation on her host:

200: Test command: /usr/bin/env "PYTHONPATH=/paddle/build/python/build/lib-python" "/usr/bin/python2.7" "-u" "-m" "unittest" "--verbose" "test_selected_rows"
200: Test timeout computed to be: 9.99988e+06
200: test_selected_rows (test_selected_rows.TestSelectedRows) ... ERROR
200:
200: ======================================================================
200: ERROR: test_selected_rows (test_selected_rows.TestSelectedRows)
200: ----------------------------------------------------------------------
200: Traceback (most recent call last):
200:   File "test_selected_rows.py", line 34, in test_selected_rows
200:     self.assertEqual(0, selected_rows.rows()[0])
200: TypeError: Unable to convert function return value to a Python type! The signature was
200: 	(self: paddle.fluid.core.SelectedRows) -> paddle::framework::Vector<long>
200:
200: ----------------------------------------------------------------------
200: Ran 1 test in 0.000s

It may be a bug in only CPU, and our CI system doesn't run unit tests with WITH_GPU=OFF, so how about turn on the unit tests on CPU? It would increase few minutes (GPU unit tests run 6m), but it may be worth.

[helinwang]

Maybe we should run CPU test as well, when WITH_GPU=ON? I think by definition test means "run all available tests", and the available tests when WITH_GPU=ON includes the CPU tests.

[typhoonzero]

If build with GPU, CPU tests also runs.
I'm wondering why CPU only test can differ from run both CPU and GPU tests?

[luotao1]

I'm wondering why CPU only test can differ from run both CPU and GPU tests?

Yes, I'm wondering as well.

[luotao1]

Discussed with @wangkuiyi, and he supports to turn on the unit tests on ONLY_CPU mode after fixing related fails.