To build :
% make distclean
% make build=site
For example :
% make build=sogo-demo
To activate debugging info, add to site.js :
pref("javascript.options.showInConsole", true);
pref("nglayout.debug.disable_xul_cache", true);
pref("browser.dom.window.dump.enabled", true);
pref("javascript.options.strict", true);
If you want to uninstall a previously installed extension from SOGo's updates.php script, just set its version number to "disabled" in the php script.