There is handy function to checkout and configure the trunk - right click Assembly list...
Where is this 'Assembly list...' that I need to right-click?
(I did "svn checkout svn://www.ultimatepp.org/upp/trunk/" to get the (current?) version I used)
I'd rather use the to-be-updated tarball in the Nightly builds - it is much less of a hassle to use than svn directly.
When you start TheIDE, there is "Assembly" list in the left of package selection dialog.