Summary: The "attaching failed" error provides no context and is a handled error, so we don't need to elevate this to a warning. We also see a socket warning on stderr every time we start up logging through simctl, so we don't need to treat that as an error. Reviewed By: nikoant Differential Revision: D26228037 fbshipit-source-id: 1938dadd54499462e1fd614c9477f738661c387b