Re: error building poke-mode.elc

[Jose E. Marchesi]

> Building the current master branch on a system with Emacs 24.5.1,
> I get this error:
>
> ========================================================================
> make[2]: Entering directory '/media/develdata/devel/POKE/poke/etc'
> if test 'emacs' != no; then \
>   am__dir=. am__subdir_includes=''; \
>   case poke-mode.elc in */*) \
>     am__dir=`echo 'poke-mode.elc' | sed 's,/[^/]*$,,'`; \
>     am__subdir_includes="-L $am__dir -L ./$am__dir"; \
>   esac; \
>   test -d "$am__dir" || /arch/local/x86_64-linux/bin/mkdir -p "$am__dir" || 
> exit 1; \
>   emacs --batch \
>       \
>     $am__subdir_includes -L . -L . \
>     --eval '(if (boundp (quote byte-compile-dest-file-function)) (setq 
> byte-compile-dest-file-function (lambda (_) "poke-mode.elc")) (defun 
> byte-compile-dest-file (_) "poke-mode.elc") )' \
>     -f batch-byte-compile 'poke-mode.el'; \
> else :; fi
> Loading 00debian-vars...
> Loading /etc/emacs/site-start.d/50autoconf.el (source)...
> Loading /etc/emacs/site-start.d/50cmake-data.el (source)...
> Loading /etc/emacs/site-start.d/50dictionaries-common.el (source)...
> Loading debian-ispell...
> Loading /var/cache/dictionaries-common/emacsen-ispell-default.el (source)...
> Loading /var/cache/dictionaries-common/emacsen-ispell-dicts.el (source)...
> Loading /etc/emacs/site-start.d/50gnugo.el (source)...
> Loading /etc/emacs/site-start.d/50python-docutils.el (source)...
>
> In toplevel form:
> poke-mode.el:169:1:Error: rx form `regexp' requires args satisfying `stringp'
> make[2]: *** [Makefile:2022: poke-mode.elc] Error 1
> ========================================================================
>
> Since Emacs is now a build prerequisite, it should be mentioned in the
> third section of the DEPENDENCIES file.

Emacs is not a strict dependency.  From the Automake manual:

   Automake will byte-compile all Emacs Lisp source files using the
   Emacs found by ‘AM_PATH_LISPDIR’, if any was found.

If no Emacs is found in the build system, AM_PATH_LISPDIR will set
lispdir to a default and Automake will not try to byte-compile the .el
files.

Now, _if_ Emacs is installed, then clearly the modes are requiring a
recent enough version of Emacs.  This is annoying.

I see two alternatives:

a) We change dist_lisp_LISP to dist_lisp_DATA so Automake will never try
   to byte-compile the elisp files.

b) We document a minimum version of Emacs in DEPENDENCIES.