Re: [PATCH] Add facility to collect stderr of async subprocess

[Eli Zaretskii]

> From: Daiki Ueno <address@hidden>
> Cc: address@hidden
> Date: Tue, 31 Mar 2015 16:27:10 +0900
> 
> > In addition, this:
> >
> >>   (let ((stderr (make-pipe-process :name "stderr")))
> >>     (make-process :name "test"
> >>                   :buffer (current-buffer)
> >>                   :command (list (expand-file-name "./test.sh"))
> >>                   :stderr stderr)
> >>     (set-process-filter stderr ...))
> >
> > introduces a new concept whereby a process object ('stderr' in this
> > case) can be passed to another subprocess, which AFAIK was not
> > possible until now, at least not on MS-Windows.
> 
> I don't get your concern here.  The above code is merely meant to pass
> the actual FD of the child end of pipe, through an opaque Lisp object
> `stderr'.

Then perhaps there's no problem.

However, please note that the call to emacs_pipe2 in make-pipe-process
will hit an assertion in w32.c's implementation of pipe2.

> I've just set up MSYS2 and tried the Emacs w64 build instruction[1] (and
> also obtained a copy of Hart's book).  Let me try again later.
> 
> Footnotes: 
> [1]  
> http://sourceforge.net/p/emacsbinw64/wiki/Build%20guideline%20for%20MSYS2-MinGW-w64%20system/

I'd be happier if you used nt/INSTALL instead, and reported any
changes/additions needed for supporting MSYS2.

Thanks.