patch no longer creates reject files in the context format, contrary to what the manual page specifies. It's behavior is similar to Ubuntu's (http://manpages.ubuntu.com/manpages/trusty/man1/patch.1.html), but it's missing the option to select the reject format (through --reject-format or other ways). Personally I prefer the old behavior, since context diffs are much easier to read and to spot why the rejection occurred, but at least I'd like the option to select it.
Obviously no interest, worked around locally and moving on.