Currently, for an invalid stage like:

{

  $lookup:

{     connectionName: "foo",     ...   }

}

 

The error message is below:

"(CommandFailed) Failed to create stream processor: Stage spec must contain a 'connectionName' string field in it: $lookup: Stage spec must contain a 'connectionName' string field in it: $lookup: Stage spec must contain a 'connectionName' string field in it: $lookup: Stage spec must contain a 'connectionName' string field in it: $lookup, correlationID = 17fa5cb3e2298794811349ea"

 

The error message should be:

$lookup stage spec must contain a 'from.connectionName' field in it