ENYO-2935: address review-comments (ERR messages + t9.1 failure)

- Let expected errors/exception pop & cause a log at `Generator`-caller
  level
- `t9.1` is not expected to run if `t9.0` does not

Enyo-DCO-1.1-Signed-off-by: Francois-Xavier KOWALSKI <francois-xavier.kowalski@hp.com>