How to 'Watch' only a directory in a GitHub repository?

GitHub provides RSS feeds for both directories and files that can do this. See Setting up an Github Commit RSS feed

Using that you can set up an email alert using a service like https://blogtrottr.com/ to send you an email whenever the feed is updated.

Example: To watch this directory:https://github.com/torvalds/linux/tree/master/Documentation use this atom feed https://github.com/torvalds/linux/commits/master/Documentation.atom

Example: To watch a file:https://github.com/torvalds/linux/commits/master/Documentation/Makefilehttps://github.com/torvalds/linux/commits/master/Documentation/Makefile.atom

I can't think of anything if you really need to watch a directory, but if you can get away with a single file I'm using http://www.changedetection.com/ on the raw view of the file in question. The directory view would probably change every time someone starred or watched the project, but a single file should be sufficient for a lot of people (especially with Makefile.am/CMakeLists.txt/etc. which list all subdirectories).

FWIW I'm going through an e-mail address generated by MaskMe and I haven't received any spam to that address after three months (the changedetection web site looks a bit sketchy, so I was worried).

I confirm that the "watch" feature on GitHub is at the repository level, not at the directory level.

For directory-level watching, you could implement it by, for instance, having a local process cloning, then pulling, that repo every x hours, checking the ls-tree of each new commit, and then sending you an email if an update in plugins is detected.