Well, it's not clear from the message whether it is an error or not, so if it's just a warning, I think it should say so, and omit the scary stack trace. There must be many similar dependency classes, but I only get the message once per build, so I had assumed that it was aborting some further processing.
But it seems like the plugin should not try to copy a file which doesn't exist. If the file is not part of the project, perhaps it ought not to be mentioned at all. (However, I'm not quite sure what purpose this copying has, so I could well be wrong about that.)