Unittest's subTest doesn't work with Pytest, or am I crazy?

As I understand, pytest should provide parameter information withunittest.TestCase.subtest() if a test fails. So here is something that resembles my code:

class TestStuff(unittest.TestCase):

    def test_foo(self):
        for i in range(0, 100):
            with self.subTest(msg = "seed", i = i):
                np.random.seed(i)
                n = np.random.randint(0, 30)
                self.assertGreaterEqual(28, n)

This ofcourse fails, and prints out the following:

================================================================================================== test session starts ===================================================================================================
platform darwin -- Python 3.7.3, pytest-5.0.1, py-1.8.0, pluggy-0.12.0
rootdir: /Users/foopackage
plugins: openfiles-0.3.2, arraydiff-0.3, doctestplus-0.3.0, remotedata-0.3.1
collected 7 items                                                                                                                                                                                                        

foo.py ......F                                                                                                                                                                                               [100%]

======================================================================================================== FAILURES ========================================================================================================
________________________________________________________________________________________________ TestStuff.test_foo _________________________________________________________________________________________________

self = <foo.test_foo.TestStuff testMethod=test_foo>

    def test_foo(self):
        for i in range(0, 100):
            with self.subTest(msg = "seed", i = i):
                np.random.seed(i)
                n = np.random.randint(0, 30)
>               self.assertGreaterEqual(28, n)
E               AssertionError: 28 not greater than or equal to 29

foo.py:135: AssertionError
=========================================================================================== 1 failed, 6 passed in 1.91 seconds ===========================================================================================

As you can see, there are no message about which seed (value of i) failed the test. I have read everywhere that Pytest is compatible with unittest, so I cant seem to see the problem here. Can someone explain this? Thx