Strange output when compiling

[Matthieu Vachon]

Hi,

When compiling some scheme module, either mind or even Kawa scheme
module, I often see the following ouput:

    Default case invoked for:
       opcode  = 60, "Con"

Do you know where it could came from? I searched in Kawa code base for
such string but could not find nothing (did I miss it, maybe).

It is not consistent. For example, after an `ant clean`, it is shown
two times. I do another one, I shows only on time, but at a different
location. Really strange.

It does not seems to impact anything, just a spurious output message
that should not be there.

Regards,
Matt