Running any Essence model (including an empty one) with the -log-level flag set to logdebug (or logdebugverbose) repeatedly clears the terminal during output.

(Cannot currently confirm this on a platform other than Linux)

From a quick bit of digging, the issue seems to be from this part of the definition of runLoggerPipeIO in Prelude.hs being tripped incorrectly by the logging output:

when ("[" `isPrefixOf` txt) $ do
    liftIO clearScreen
    liftIO (setCursorPosition 0 0)

This contains the only reference to clearScreen, and watching the terminal output, every time the first character post-clear is indeed a [ (e.g. in [addTrueConstraints]).