no_gen keyword at the app level turns off all generation.
Bigtop will do nothing if you have this set.
Use this if you are paranoid about someone inadvertantly rebuilding the application.
Note that the value of this statement must be true. I usually use 1 as the value.
When you try to build the example with:
bigtop -c example.bigtop all
bigtop, will do nothing (except possibly clutter the screen with falsehoods and/or warnings).