Is there some way to print infos when the interpreter running?

[majia gm]

Hi.

I'm porting libgcj and get a fail when running ecj1. I'd like to watch
how the interpreter works.
Is there any option to print some useful information when the
interpreter running?

I saw the options enable-debug and enble-libgcj-debug?  But I found
nothing in the manul on how to use these options.

Thank you.

Gm Majia