7f4fbc8756
RepositoryNotFoundException should really mean "this repository definitely doesn't exist", not "something went wrong when we tried to read this repo (maybe it doesn't exist?)". Since GitRepositoryManager could only throw RepositoryNotFoundExceptions, the easiest implementation was to wrap *all* exceptions in that class, i.e. to take the latter interpretation. We have some downstream caching code that treated RepositoryNotFoundExceptions as definite negatives, i.e. the former interpretation. This was causing poisoned caches on otherwise mostly harmless transient errors. Change GitRepositoryManager to distinguish between these two cases by using IOException for "something went wrong". This complicates the signature, but since RepositoryNotFound derives from IOException, many callers that just want to wrap-and-throw can still do so with minimal changes. Change-Id: Ib2aa2e2443cc3b530ae7fc50fe4eb20059bb16de