None I know of. But then you shouldn't issue many messages, because if you haven't got the Gimp console up you would get a modal dialog instead.
Since you are on Linux, if you are using these messages to debug maybe you can use (display ...) and (newline) instead to print things on stdout. If you start Gimp from a terminal, this should show up in said terminal (at least this is how python-fu behaves). The only downside of this solution is that you have to disable it for use by Windows users, because after 4K of output the script stalls (in my Python scripts I only output things if a specific environment variable is set).
Since you are on Linux, if you are using these messages to debug maybe you can use (display ...) and (newline) instead to print things on stdout. If you start Gimp from a terminal, this should show up in said terminal (at least this is how python-fu behaves). The only downside of this solution is that you have to disable it for use by Windows users, because after 4K of output the script stalls (in my Python scripts I only output things if a specific environment variable is set).