An anonymous reader writes in:
[W]hat should a prospective candidate to the job market do when she cannot count with a recommendation letter of her previous supervisor? I imagine some PhD students do not have a good relation with their ex supervisors, and thus this bad relation may create two possible scenarios: in some cases a supervisor may refuse doing a recommendation letter (for ex, by not answering a mail), or in other cases, the content of the recommendation letter may be more harmful than beneficial for the prospective candidate. This may be an important obstacle for getting a job.
Great query. My first immediate thought is that the clear thing to do is to move on and get outside letters. However, this doesn't address the problem that not having a letter from one's previous supervisor might seem like a red flag to search committees. And unfortunately, I'm not sure I know what to say about dealing with this issue.
Anyone have any helpful tips here?