Flaky test: test_uamiv_format_write

[max-sixty]

I've seen a couple of failures recently on this test. Flaky tests are really annoying and would be great to fix or if impossible, remove it. Does anyone have any ideas what's causing this?

________________ TestPseudoNetCDFFormat.test_uamiv_format_write ________________

self = <xarray.tests.test_backends.TestPseudoNetCDFFormat object at 0x7f15352b9d00>

    def test_uamiv_format_write(self):
        fmtkw = {"format": "uamiv"}
    
        expected = open_example_dataset(
            "example.uamiv", engine="pseudonetcdf", backend_kwargs=fmtkw
        )
        with self.roundtrip(
            expected,
            save_kwargs=fmtkw,
            open_kwargs={"backend_kwargs": fmtkw},
            allow_cleanup_failure=True,
        ) as actual:
>           assert_identical(expected, actual)
E           AssertionError: Left and right Dataset objects are not identical
E           
E           
E           
E           Differing attributes:
E           L   WTIME: 190117
E           R   WTIME: 190118

xarray/tests/test_backends.py:3563: AssertionError

[keewis]

this might be related to / a duplicate of #3711

[max-sixty]

Thanks @keewis . Closing as duplicate