Our unit tests are expected to pass every time. When they fail we are expected to fix the regression. But in some cases it is ok for a test to temporarily not pass. For example, if the test is a small regression in a minor feature and we are currently employed with other critical missions. But while the test is failing we should at least make sure it will not cause any noise like spamming out the team.
When we use NUnit, the solution is the Ignore attribute: