Test button is green but in reality, the test job failed

[janeyx99]

e.g., https://hud.pytorch.org/commit/3b4cb9ddca1cc2b92277541ff781730042bee3c5

[driazati]

The problem here is that the failure happened outside of unittest, so it wasn't included in the XML. This is pretty easy to detect (e.g. https://github.com/pytorch/ci-hud/pull/166/files#diff-3ad9e34ce5052427659516e20bceac132c7cd3e4463470c1371d9dd724b11832R139-R141), and once that lands we can unify it to once place do the same thing here (show a message explaining the issue and hide the results button)