source dir must be named 'ceylon'

[gavinking]

I wasted a whole bunch of time yesterday because I didn't realize that the plugin requires that Ceylon source resides in a directory named ceylon/, and doesn't give you any kind of error if you try to put your Ceylon code in java/.

This seems pretty lame to me, and a real gotcha for new users.

[quintesse]

But what kind of behaviour would you suggest? Because I'm guessing that the Java files in the java folder are handled by the default Java "plugin". And if that doesn't give any warnings I wonder if it would be that easy to make it give any warnings.