Easy shulker shell farm

Shulkercraft's build of EndingCredits' shulker farm, and the easiest working shulker design there is. A single shulker is transported into a scaffolding tower where its offspring are killed by fall damage, with no portals, no snow golems and no directional building, so it can go anywhere including over an ocean in the overworld. The build itself is trivial. Getting the first shulker to the site is the actual work, which is why the item list has a whole second half for it.

• Cover every face of the glass with buttons. Shulkers teleport onto it around 7:35 and escape the farm, and this is the most reported problem by a wide margin.
• Clear any chorus trees near the farm. Shulkers latch onto them and leave the killing area.
• The powered rails are optional. A minecart with a furnace moves the shulker just as well, and several builders instead push it into a boat and airlift that with a happy ghast on leads.
• Use top slabs for the rail line rather than glass, which is what most builders end up doing.
• If you are getting hit while AFK, remove the middle scaffolding, put water above the barrel and close a fence gate over your head.
• On 26.2 the shulker can stop working after taking damage. Splash it with potions of healing and give it a moment rather than starting again.