You may have heard WordPress 4.9 is out. While this seems a good improvement over 4.8, it has a new editor that uses codemirror. So what’s the problem? Well, inside codemirror is jshint and this has that idiotic no evil license. I think this was added in by WordPress, not codemirror itself.
So basically WordPress 4.9 has a file, or actually a tiny part of a file that is non-free. I’ll now have to delay the update of WordPress to hack that piece out, which probably means removing the javascript linter. Not ideal but that’s the way things go.