This came up on the gnupg-user mailing list. While it is not per se
an autoconf problem, I should think that autoconf must provide some
workarounds to work under MacOS X. Or is it a matter of configuring
zsh differently? The failing line of code quote below is quite common.
> >>The line
> >>
> >>missing_dir=`cd $ac_aux_dir && pwd`
> >>
> >>from configure.in doesn't work under Mac OS X.
> >
> > Why not? Where exactly does it fail?
>
> As I mentioned before this is what happens: OS X uses zsh as /bin/sh (not
> sure if this is relevant). In a simple test script the above line gives the
> expected result. However, in the context of gpg's configure script it
> results in two lines! The 'cd' command isn't silent but returns the new
> current directory. The following 'pwd' adds another line. The behavior is
> similar to that of bash if the variable CDPATH is set. However, this is not
> bash and CDPATH is explicitly unset. So I really don't know why this
> happens. I'd guess that it's some "feature" of zsh, but what do I know?