Why does Googlebot crawl for /mobile/* and /m/* pages that are not referenced anywhere on your website?
This had us scratching our heads because we built a responsive site so did not require a separate mobile version that Google seems to imply we have one when we check the errors in the search console in Webmaster tools.
Digging around for some clues as to why these errors where flagged up yield hardly any results on Google search - except for https://productforums.google.com/forum/#!topic/webmasters/k3TFeCkFE0Q and https://productforums.google.com/forum/#!topic/webmasters/56CNFxZBFwE
We think this is a very minor issue though but annoying to see the errors. Nevertheless a quick solution is to either redirect /mobile and /m to your homepage. Or add to your robots.txt file to disable it from being indexed. However, make sure your site is responsive to begin with so that you do not need a mobile version and Google favours responsive sites.
If you need to make your website responsive, contact me