Migrate produce files in app_root/db

Hi, as I told in a previous post engine_migrate generate files in
app_root/db, not in engine/db (so does the controller generator)

As a consequence, every time I generate a new migration I have to move
the file by myself, not a big deal but -> schema.rb is ALSO in app/db
not in engine/db so, I’ve symlinked engine/db with app/db.
I find this kind of trick quite strange and I really wonder if there’s
something wrong somewhere because I didn’t found anything in the doc
about the need to symlink this file.