(whitespace-cleanup-mode . t) in dir-locals has no effect because

[vspinu]

(whitespace-cleanup-mode . t) in dir-locals has no effect because whitespace-cleanup-mode-write-file is not added to write-file-functions in that scenario.

GNU Emacs 25.0.50.3 (x86_64-unknown-linux-gnu, GTK+ Version 3.12.2) of 2015-05-27

[purcell]

Hmm. That actually works fine for me, with a similar version of Emacs. Can you please provide steps to reproduce this, starting with a clean (-Q) instance of Emacs?

[vspinu]

With the following in .dir-locals.el

((emacs-lisp-mode (whitespace-cleanup-mode . t)))

simply emacs -q and M-x load-library whitespace-cleanup-mode. Then visit a an .el file in that directory. Check for vars: whitespace-cleanup-mode is t, but write-file-functions is nil.

[purcell]

Right. I was testing it wrong, and I can confirm this behaviour.

But it turns out there's a different syntax for enabling minor modes via .dir-locals.el:

((emacs-lisp-mode (mode . whitespace-cleanup-mode)))

[purcell]

So I think that means this issue is invalid...

[purcell]

I found that tip via a stackoverflow answer, but the emacs manual says not to use mode for minor modes. So I'm not sure what the right answer is here.

[akirak]

I've implemented a workaround to solve this issue (#15).

1. Set the default value of whitespace-cleanup-mode-enabled to nil.
2. Turn on global-whitespace-cleanup-mode.
3. Add the following .dir-locals.el.

((emacs-lisp-mode (whitespace-cleanup-mode-enabled . t)))

[dabrahams]

I think the right answer, per the emacs manual, is to use (eval ignore-errors (whitespace-cleanup-mode)) in .dir-locals

[purcell]

What's interesting is that mode seems to work perfectly for minor modes in .dir-locals.el, where groups of variable values are applied in pre-specified major modes, but mode gets interpreted as the name of the major mode in file-local variables.