bug#10125: 24.0.91; package.el (org): Macros in tar packages & order of byte compilation

[Eli Zaretskii]

> From: Glenn Morris <rgm@gnu.org>
> Cc: Eli Zaretskii <eliz@gnu.org>, 10125@debbugs.gnu.org,  
> stelian.iancu@gmail.com
> Date: Thu, 24 Nov 2011 14:09:38 -0500
> 
> I guess nobody ever expected the package manager to be used to load a
> different version of something that was already in Emacs.

Indeed.  Because doing this is asking for trouble: Emacs loads
packages in a certain order to avoid several subtle problems; doing
that in a different order defeats that.

I think package.el should test with featurep whether a version of a
package is already loaded, and refuse to load it into a running
session, or at least display a warning to that effect, suggesting to
restart Emacs.