The debug scene for senna is jump senna_dildo
Edit: attached is a rpy script I created a while back that extracts, sorts, and outputs unique labels to a text file in the renpy game's executable folder ("labellist.txt"). If you put this script into your game folder, it will run on startup and give you a complete listing of all jump labels in the renpy game. It checks to see if the file is already created to ensure it doesn't slow down your startup times by recompiling the list on every startup.
For example, here's what gets generated for 8.4a: