Major - P3 If you insert an invalid document (such as {_id:1}) into the admin.system.roles collection, then when you start up mongod you get the following message in the logs
warning: Skipping invalid role document. NoSuchKey Missing expected field "role"; document { _id: ObjectId('52b89d3f891856e1f39f7d33') }
Note that this message does not indicate anywhere what collection this document came from or what process was trying to read it.
I propose changing the message to saying something like:
warning: Skipping invalid admin.system.roles document while initializing role graph to calculate privileges for user-defined roles: NoSuchKey Missing expected field "role"; document { _id: ObjectId('52b89d3f891856e1f39f7d33') }