Re: master 32fe187bdf1: Install rcs2log within Emacs packages for Android

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org
> Date: Thu, 24 Aug 2023 18:11:23 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > What is the significance of ANDROID_STUBIFY for these variables?
> 
> ANDROID_STUBIFY is t when portions of the Android port code are compiled
> to run on the build machine (for compiling Lisp and generating the Org
> manuals), while the Mailutils defines are non-nil when Emacs isn't
> distributed with its own movemail.
> 
> > Cannot the proper values be determined in Lisp using some other
> > evidence or variable?
> 
> Not by any means I know of -- and I'm averse to introduce two more
> DEFSYM and feature variables for this purpose.

Why isn't system-type or something similar enough for that?

And if that's not good enough, I think we should have a Lisp variable
or function to do this job, because these issues will keep popping up,
and doing all of that in C, just because we don't have the information
in Lisp, is not a good idea.  We do stuff like that in other cases,
cf.  noninteractive, window-system, daemonp, etc.

> Besides, what's the purpose of moving them to Lisp?

First, it's cleaner.  And second, these issues will happen in Lisp
code as well, and inventing a primitive for each one of them is not
the best idea.

> We also define shell-file-name, exec-suffixes, exec-directory,
> data-directory, doc-directory, and even configure-info-directory
> within callproc.c, which is the natural location for such things.

I don't see how these are relevant.  These variables are actually used
in callproc.c, with the single exception of configure-info-directory.