🚀 go-pugleaf

While installing gnu emacs on two different architectures I got caught
by the configuration comments.  I thought I could share the sources
and lisp libraries and just install the binaries (xemacs and auxiliary
programs like "env") in seperate directories.

The configuration variable EXEC_PATH in paths.h seemed to be Just The
Right Thing, because it is commented:

/* the extra search path for programs to invoke.
 This is appended to whatever the PATH environment variable says
 to set the Lisp variable exec-path and the first file name in it
 sets the Lisp variable exec-directory.  */
#define PATH_EXEC "/usr/local/lib/emacs/etc"

This directory (in the build-tree) is shared, I just thought that I
could change it to the (architecture-specific) /usr/local/bin and
install the aux binaries there.

This didn't work out.  Problems:

1.: The exec-directory is used in some lisp libraries to locate the
    build tree.  For example, (concat exec-directory "../lisp/") might
    be used to reference the standard lisp directory.  Particularly,
    exec-directory is used to locate the DOC file.  This is clearly
    *not* told in the EXEC_PATH comment.

2.: Aux binaries like "movemail" or "env" are searched for only in
    exec-directory, not along the entire $PATH.

Please get the comments in paths.el right, whatever that may be.

Finally, I configured emacs with EXEC_PATH as given (pointing into the
build-tree .../etc), moved the aux binaries into the different
/usr/local/bin/directories on different machines and made symbolic
links from the /etc directory to the true binaries.