[ESS] Installing two different versions of Emacs and of ESS on Debian stable

[Chris Evans]

I run Debian stable on my main laptop and a few other machines (web server, backup) and such is the pace of development in ESS that I've been aware for a long time that the Debian stable version of Emacs (23.4.1) holds me back from exploring the latest capabilities of ESS and I'd like to follow that because I'm torn between Rstudio, which gets me a the ability to weave .Rmd to output into html, pdf and .  

However, I'd like to have the Debian stable version of Emacs and ESS available.  I think I've now got something set up that works and I think if I add a bit to cron.daily I can even make sure that ESS is updated daily if there have been changes in the subversion repository.  However, I'd like to check what I've done with the experts on the list to see if it's the best way to do this.

What I've done is to download the latest version of Emacs as source from the Emacs site and make install so I now have two versions of Emacs: the default Debian 23.4.1 (residing in /usr/bin/ ) and version 24.4.1 (in /usr/local/bin/).  

I've added this to /home/chris/.emacs:
(cond
     ((string-match "23.4.1" (emacs-version))
        (message "customizing GNU Emacs for 23.4.1")
        (require 'ess-site)
        )
     )
(cond
     ((string-match "24.4." (emacs-version))
        (message "customizing GNU Emacs for 24.*")
        (load "/usr/share/emacs/site-lisp/ess-site")
        )
     )

Finally I've put this as a file updateESS in /etc/cron.daily:
#!/bin/bash
cd /home/chris/Downloads/ESS
/usr/bin/svn update > /home/chris/ESSupdate.msg
/usr/bin/make >> /home/chris/ESSupdate.msg
/usr/bin/make install >> /home/chris/ESSupdate.msg
cat /home/chris/ESSupdate.msg | mail -s "Updated ESS" chris...

(where ... is the rest of my address, trying to reduce spam harvesters' joy here!)

The updateESS file seems to work and I think all is now hunky dory with the two versions of Emacs available (I've created desktop icons to invoke each).. Does that look right to experts here?  Clearly I'll have to update those lines in .emacs when the latest emacs moves beyond 24.4.* and when Debian moves beyond 23.4.1 and I'm sure there are clever ways of parsing emacs-version.  

TIA,

Chris

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