[Emacs Mac port](https://bitbucket.org/mituharu/emacs-mac/src/master) is YAMAMOTO Mitsuharu's Mac port of GNU Emacs.
I have been trying to use doc-view on djvu files which resulted in this traceback (I have trimmed it down for relevant informations)
Debugger entered--Lisp error: (wrong-number-of-arguments (3 . 3) 1)
doc-view-multiplex-conversion(...)
doc-view-djvu->tiff-converter-ddjvu(...)
...
Where I found the procedure in question is `doc-view-djvu->tiff-converter-ddjvu`, with an ill-defined form:
(defun doc-view-djvu->tiff-converter-ddjvu (djvu tiff page callback)
"Convert PAGE of a DJVU file to bitmap(s) asynchronously.
Call CALLBACK with no arguments when done.
If PAGE is nil, convert the whole document."
(doc-view-multiplex-conversion
(lambda (tiff callback &optional resolution)
(doc-view-start-process
"djvu->tiff" "ddjvu"
`("-format=tiff"
;; ddjvu only accepts the range 1-999.
,(format "-scale=%d" (round (or resolution doc-view-resolution)))
;; -eachpage was only added after djvulibre-3.5.25.3!
,@(unless page '("-eachpage"))
,@(if page `(,(format "-page=%d" page)))
,djvu
,tiff)
callback)
tiff callback)))
The problem is that `tiff callback` are enclosed within the lambda and not part of the funcall to `doc-view-multiplex-conversion`. Applying this change fixes the problem for me.
Interestingly, upon checking the \[[https://github.com/emacs-mirror/emacs/blob/emacs-28/lisp/doc-view.el\](doc-view](https://github.com/emacs-mirror/emacs/blob/emacs-28/lisp/doc-view.el](doc-view) file) at emacs 28 github mirror, they are slightly different definitions, where the mac-port has wrapped it with `doc-view-multiplex-conversion`.
Naturally I could not find any place to raise this issue. Because firstly, I am not very used to using`report-emacs-bug` and the mailing list. Secondly, this is related to Emacs mac port not exactly Emacs (see my point just above). So here I am, wonder what actions I could take to make this get noticed and fixed.