potential race-condition in Repository#has_local_branches?

it's so weird that we are seeing these errors since every call site I see for has_local_branches? is preconditioned on exists?, either explicitly or through Repository#cache_method_output. Also because of cache_method_output this error is silent on the rails side. What is possible but seems extremely unlikely to me is that the repository is deleted in between checking exists? and calling has_local_branches?. I don't have any solutions to propose for that case at the moment. Since the volume of this error doesn't look too high, I'd say this doesn't block the AT.

gitaly#685 (comment 50021065)

Only getting at most 1 error per hour out of 4-5 requests per second so not extremely high priority.