[Debug] add some file link format handling

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

this will make it an empty string if it is not replaced, not ``null``. It should be ``<argument>null</argument>`` instead