Re: package.el: bytecode portability across emacs versions

[Richard Stallman]

    I know that sharing bytecode is bad.  I just didn't know what to do
    about it.

You could put the bytecode in
/usr/local/share/emacs/VERSION/site-lisp, which is a standard element
of load-path, version-specific.  The source code could go in
/usr/local/share/emacs/site-lisp.  If package.el finds the source
code and not the binary, it can compile for the current Emacs version.