Zombified Piglins spawn in places they shouldn't - PortalbasedPiglin Farm

[JoField08]

Expected behavior

Zombified Piglins should spawn in the nether portals

Observed/Actual behavior

Zombified Piglins spawn near to nether portals, outside the portals on random blocks.
Most of the time under the portals.

Steps/models to reproduce

1. Build a regular Zombified Piglins Farm and start it (you might have to replace the glass from ilmango's farm to stone or any other solid block)
2. Wait 5-10 minutes
   -> Piglins will spawn next to portals or under them
   https://i.imgur.com/eCeAgGl.png

Plugin and Datapack List

https://i.imgur.com/fFcGgvY.png

Paper version

https://i.imgur.com/siuurBO.png

Other

Other servers are also affected by this issue. (-> Other plugins should not be the reason for this issue)
There is also an issue on Folia PaperMC/Folia#320

[ammodev]

Can confirm. Happens for us as well.

[Warriorrrr]

I was not able to observe any zombified piglins spawnin under/next to portals both using the world download from the linked video and by making a simple portal and digging a hole under it. Please provide some more reproduction steps since I'm not sure what else to do to be able to reproduce this.

[JoField08]

Try this map

• make sure the difficulty is set to hard
• start the farm
• you have to hit the piglins with a sword
  --> after a few minutes piglins will spawn on the floor

I tested this to make sure only paper is responsible for this issue. There were no other plugins on the server.

This server is running Paper version 1.21.4-138-main@5395ae3 (2025-02-02T21:42:11Z) (Implementing API version 1.21.4-R0.1-SNAPSHOT)
You are running the latest version

[Warriorrrr]

I can confirm the issue now, the piglins that spawn under the portal are from the zombie reinforcement feature, which shouldn't be a thing for zombified piglins

[Warriorrrr]

After looking a bit more I'm now not certain if this is a feature or a bug, piglins being able to spawn reinforcements is listed on the wiki as a feature.
Edit: most likely a feature, closing as WAI

[JoField08]

You can try out the farm in Vanilla. There are no piglins that spawn around the portals.
As far as I know, the reinforced feature only applies to naturally spawned zombies / zombified piglins.
And I'm guessing it's not a new feature for piglins that spawn from portals.
Otherwise youtube etc. would be full of content around this new change!?
@Warriorrrr

[Progeilo425]

@Warriorrrr This issue must be fixed

[Warriorrrr]

Sorry for closing too soon, hadn't tested it on vanilla yet since I saw that line on the wiki and assumed it was WAI. Vanilla must somehow not be following the same code path we do for portal piglins and doesn't set the leader bonus there

[Warriorrrr]

Forgot to set the difficulty to hard when moving the world to vanilla and the leader bonus for piglins from portals also works there after all, I think I'll just leave this for someone else to pick up at this point

[Malfrador]

This seems to be working as intended.
I tested it both on the latest Paper build and in vanilla, using the provided map with difficulty hard. Both in Vanilla and Paper, a zombiefied piglin is spawned as reinforcement after some time, as evident by them having a minecraft:reinforcement_callee_charge attribute modifier. Those can spawn in any free space around the leader and occasionally even spawn in the chamber below the farm.

An easy way to test this is by speeding up time with /tick rate (though Paper is able to sustain a much higher rate here than the vanilla server).

This is a Java Edition-only feature, so maybe you tested against Bedrock? Additionally, this was recently (1.21.2) changed to actually spawn zombified piglins and not normal zombies.