There are some links in the docs that get 404 recently:

http://man7.org/linux/man-pages/man1/curl.1.html in repl.html (1 link).
http://man7.org/linux/man-pages/man3/uname.3.html in os.html (3 links).

They are wrongly rendered:

They have been fixed with manually added URLs in #10244 and #15463, but have been reverted to autogenerated URLs (with autogenerated URLs being prioritized/rewritten above manual URLs) in the #17479

cc @DiegoRBaquero and @apapirovski as maybe more well-informed about the tools/doc/html.js script.