Current behavior
If an empty string is passed as a zr method, the getcredentials utility is called.
The error message is then put in the template, and error is ignored.
Once Jinja "correctly" succeeded, YAML fails.
**Example*
- DB_USER: A positive integer id is expected. - DB_PASSWORD: Usage: getcredentials <id> [password|username|title] <======================
New behavior
The zr method won't call the utility without a valid key.