Comment 4 for bug 1732705

Well, on ubuntu, it'd be GNU diff, wouldn't it? :)

I've traditionally worked around this by specifying --using as well; if you tell it the diff program, it didn't pretend it knew to add any arguments other than those you specify.

In 3.2 releases and branch, it's further broken due to bug 1977988 breaking --diff-options more generally...