Description of the issue
This is related to #4284 and #3175.
In an older version we had some javascript code for a now removed reporting module.
The alerts for those since removed libraries still show up in the report.
https://lgtm.com/projects/g/spockframework/spock/?mode=list
It even shows a warning, that the javascript error message are based on a different commit.

It also lists a low code quality for the hence removed javascript.

A possible workaround could be to include a dummy javascript file, just so that the javascript check doesn't fail and recognizes that there are no issues left. However, that should not be necessary IMO.