In a recent deploy of this blog – which is powered by jekyll and github-pages, I found out that a tags stop working. Those links were broken.

After a quick study, I found a hint in github/pages-gem/releases/tag/v225

Apparently GitHub pages did a change on 2022-03-04. Now you need to pass UNSAFE option to jekyll-commonmark-ghpages via commonmark options in order to make it work.

In my case, I add the UNSAFE option, deploy again and it’s back to normal.

in _config.yml:

-  options: ["SMART", "FOOTNOTES"]
+  options: ["UNSAFE", "SMART", "FOOTNOTES"]
  extensions: ["strikethrough", "autolink", "table"]

They did put a little warning in github/jekyll-commonmark-ghpages saying that

The UNSAFE option is required for HTML rendering.

Not sure if they announced somewhere, but I only noticed it when my pages broken 🥲

Note that when running jekyll serve locally, it may show the following warning:

CommonMark: UNSAFE is not a valid option

Which is fine, you can ignore it.

Hope this help.