The resharding coordinator calls calculateParticipantShardsAndChunks, which can eventually call into InitialSplitPolicy. InitialSplitPolicy uses numbered error codes in various places, which can end up being reported as the failure reason if they cause resharding to fail.

Resharding should return named error codes as a failure reason if it fails, so either wrap the errors returned from InitialSplitPolicy with a named error code, or directly replace the numbered error codes in InitialSplitPolicy with named ones.