Both failed the first time the world they describe existed. They named a post by slug, so renaming placeholder-borborygmus to placeholder broke one; and they demanded the well-known key be exactly the URI, which it never is, because the end-of-file-fixer hook appends a newline on commit. The link-tag pair becomes one test over every built post: the tag is there when the post's frontmatter has an atUri, and absent when it does not. It reads the atUri rather than assuming which post carries one, so publishing a post cannot break it either. Sequoia writes the value quoted, hence the quotes coming off.