bug#46837: Makefile dependencies for info files

[Eli Zaretskii <eliz@gnu.org>]

> From: Glenn Morris <rgm@gnu.org>
> Cc: 46837@debbugs.gnu.org
> Date: Fri, 05 Mar 2021 14:23:26 -0500
> 
> Eli Zaretskii wrote:
> 
> > So the poor souls who don't have makeinfo could "touch info/emacs.info"
> > and have the build continue instead of failing?  If this works, I
> > think it's a fine solution.  It would be even better if the advice to
> > "touch info/emacs.info" would be included in the error message printed
> > when we find no makeinfo.
> 
> I would not recommend that, which in any case would only get past the
> configure step, leaving make to fail.

So it will fail even if all the Info files are already in the tree,
when makeinfo is not available?  Or are you saying that in order for
"make" not to fail one must touch not just info/emacs.info, but also
all the rest of the *.info files?

> Instead I would recommend installing makeinfo, which is widely
> available and where even an ancient version will do.

No argument there, I was talking about fire escape.  After all, we are
removing a "feature" that existed in previous releases.  It would be
good to tell people how to get back the old behavior, I think.