Jon Henshaw posted a screen shot of Google showing him and only him a message in the desktop search results that his pages have AMP implementation errors. He spotted the error when doing a search and noticed that in the snippet, it has a link that reads "your page has AMP implementation errors."
He posted this on Twitter:
Google did this for mobile friendly warnings as well, so I guess it makes sense for AMP errors.
Google's Gary Illyes asked on Twitter if we found that useful? Why not?
Forum discussion at Twitter.