how to run makeinfo in a subprocess on Windows?

[Stephen Leake <stephen_leake@stephe-leake.org>]

I'm working on automatically publishing html doc files for ELPA
packages.

When the source for a doc is .texi, that requires running "makeinfo".
elpa-admin does this via call-process, doing something like:

(let ((default-directory "c:/Projects/elpa/packages/ada-mode/")
      (docfile "ada-mode.texi")
      (html-file "doc/ada-mode/ada-mode.html"))
  (call-process "makeinfo" docfile nil nil "--no-split" "--html" "-o" html-file))

and that works fine on Debian.

However, on Windows, I get :
let: Searching for program: Permission denied, makeinfo

I suspect the problem is that "makeinfo" is actually a perl script, and
it has "#! /usr/bin/perl" on the first line. On Debian, the lower-level
system call that actually starts the process apparently knows how to
handle that; it starts perl, and passes it "makeinfo" and the other args.

However, on Windows that doesn't happen. I suspect if I was running the
mingw64 version of Emacs, it would work. The emacs I'm running is built
using mingw64 tools, but it uses the native Windows OS, not the
mingw64 layer.

Is there a suggested way to handle this? I can just add code to
elpa-admin to run perl explicitly when on Windows, but I'm hoping
there's already code somewhere that handles this.

-- 
-- Stephe