On Wed, Oct 2, 2019 at 12:40 AM Richard Copley <rcopley@gmail.com> wrote:

>That's puzzling.

Ok.

I get your message if I add to PATH a non-existent (or, I suppose,
non-accesible) directory.

So, if you have such a directory in your PATH, the message you get is
correct, because it happens before call-process can totally determine that
it can not find "xyzzy".