We use Jenkins' Git plugin to run our tests, but we prefer not to clean
workspace before each build and reuse the code in the workspace instead. This
makes testing much faster. Unfortunately, sometimes the Git information on the
workspace gets corrupted and git fetch no longer works (unrelated to the Git
plugin). This means that future build on that workspace will fail unless the
workspace is cleaned.
It would be very good if Jenkins' Git plugin had the ability to clear the
workspace before doing a retry.