Downgrading a Package in MacPorts

MacPorts installed a new version of XEmacs and it broke things. So instead of fixing it I just went back to the previous version.

Here's how I did it:

1. Create a local repository in ~/lib/macports/local:
   
   % mkdir ~/lib/macports/local
   
   
2. Add the local repository to /opt/local/etc/macports/sources.conf:
   
   file:///Users/jim/lib/macports/local
   
   
3. Find the previous revision of XEmacs:
   
   % svn log http://svn.macports.org/repository/macports/trunk/dports/editors/xemacs
   
   It's r141410.
   
   
4. Check it out (into ~/lib/macports/local):
   
   % svn co --revision r141410 http://svn.macports.org/repository/macports/trunk/dports/editors/xemacs/ editors/xemacs/
   
   
5. Run portindex on the local repository:
   
   % portindex ~/lib/macports/local
   
   It should report: "Ports successfully parsed: 1"
   
   
6. Now port list xemacs shows both versions.
   
   xemacs  @21.4.22  editors/xemacs
   xemacs  @21.5.16  editors/xemacs
   
   
7. Install the local version
   
   # port install xemacs @21.4.22
   
   

That's it.