No way (flaws or build log) to detect errors in {{CSSInfo}}

Summary

The macro {{CSSInfo}} uses mdn/data to display its content.

When there is no matching entre in mdn/data, the macro generate a text in red as error:

This is good, but not enough: we detect such error only by visiting the page.

We need a way to detect all pages in error. For similar problems, errors are displayed in one of the two following ways:

• As a flaw (this is the case when the {{Compat}} macro doesn't find the info)
• In the build error log (this is the case when a Prism language tag is not supported).

Both cases allow us to find, track and fix these problems (I have no strong feelings)

URL

http://developer.mozilla.org/en-US/docs/Web/CSS/font-palette

Reproduction steps

1. Go to http://developer.mozilla.org/en-US/docs/Web/CSS/font-palette
2. There is the red message but nothing in the build log or in the flaws

Expected behavior

An error in the flaw list OR in the build log (no strong feeling about which one is the best!)

Actual behavior

No error outside the page itself

Device

Desktop

Browser

Chrome

Browser version

Stable

Operating system

Android

Screenshot

No response

Anything else?

No response

Validations

• I have read the Community Participation Guidelines.
• I have verified that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• I have checked that this is a concrete bug. For Q&A open a GitHub Discussion.

Start at the {{CSSInfo}} macro and the Rari build and error-reporting path, reproducing the missing mdn/data entry at the linked font-palette page. Done means the missing entry is reported outside the rendered page, either in the flaw list or in the build error log.