This has an explcit unit test already which somehow passes at least some of the time. I suspect it passes because under some conditions the actual KV delete fails and returns non-zero as well as printing the warning which is what is being checked for in the test.
For some reason despite working for quite some time like this, I now have a branch in which this test fails consistently. It may be a timing/env issue where another process running an agent causes the delete to be successful so the command returns a 0 by chance. Either way this is clearly wrong and fixing it stops the test being flaky in my branch.
Paul Banks