Comment 2 for bug 720853

The 'index' command used here is from the bzr-search plugin. However, the cause of the exception is the recursive method bzrlib.btree_index.BTreeBuilder._add_key so this may still be a core bzrlib problem really. A possible approach to fxing this bug would be rewriting that function to be iterative instead. Need some input from someone who knows the btree_index code.