Re: Wrong PATH in MSYS2/MINGW64 builds?

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 28 May 2015 23:51:59 +0200
> From: Angelo Graziosi <angelo.graziosi@alice.it>
> CC: emacs-devel@gnu.org, alexey.pawlow@gmail.com
> 
> > I think your problem is with exec-path (which is derived from PATH),
> > not with PATH directly.
> >
> > IME, it's a bad idea to have exec-path inside Emacs be different from
> > PATH outside Emacs, because then you'd have subtle differences between
> > Emacs looking for programs and programs it invokes (such as the shell,
> > for example) looking for programs.  So my advice is not to patch Emacs
> > that way.
> >
> 
> Shouldn't the option
> 
>    --libexecdir="${MINGW_PREFIX}/bin"
> 
> (added to "configure") fix this issue (being 
> MINGW_PREFIX=/c/msys64/mingw64)?

The libexec directory is for auxiliary programs that come with Emacs,
about which we _know_ how Emacs will invoke them.  (Example: hexl.)
That directory will indeed be added to exec-path, but it will then
create the very problem I warned against: the shell will not search
that directory, and so Emacs features that invoke shell commands (via
shell-command etc.) might mysteriously fail.  IOW, visiting
bzip2-compressed files might start working for you, but other features
using bzip2 via shell commands might still fail.

So no, this is not recommended.