Rapier native panic (index out of bounds) when a player holding a TACZ weapon enters ragdoll

[Steam2208]

Context

Server crashes with a native Rapier panic (index out of bounds) whenever a player is put into a ragdoll state (via sable_player_ragdoll manual trigger or ragdoll_reactions auto-trigger) while holding a weapon from TACZ (Timeless & Classics: Zero). Reproduced multiple times in the same session, only when a TACZ weapon is in hand — has not been reproduced with vanilla items in hand.

Steps to reproduce

1. Install TACZ (tacz-neoforge-1.21.1-1.1.8-hotfix-r6) alongside Sable + sable_player_ragdoll.
2. Equip any TACZ weapon in the main hand.
3. Trigger a ragdoll on the player (manual keybind, fall damage, explosion, hit, etc. — any trigger works).
4. Server crashes with a native panic during the physics tick.

Crash log

java.lang.RuntimeException: Rapier native panic: index out of bounds: the len is 8 but the index is 8
	at dev.ryanhcode.sable.physics.impl.rapier.Rapier3D.step(Native Method)
	at dev.ryanhcode.sable.physics.impl.rapier.RapierPhysicsPipeline.physicsTick(RapierPhysicsPipeline.java:159)
	at dev.ryanhcode.sable.sublevel.system.SubLevelPhysicsSystem.tickPipelinePhysics(SubLevelPhysicsSystem.java:278)
	at dev.ryanhcode.sable.sublevel.system.SubLevelPhysicsSystem.tick(SubLevelPhysicsSystem.java:237)
	at dev.ryanhcode.sable.api.sublevel.SubLevelContainer.lambda$tick$0(SubLevelContainer.java:147)
	at it.unimi.dsi.fastutil.objects.ReferenceArrayList.forEach(ReferenceArrayList.java:719)
	at dev.ryanhcode.sable.api.sublevel.SubLevelContainer.tick(SubLevelContainer.java:147)
	at dev.ryanhcode.sable.api.sublevel.ServerSubLevelContainer.tick(ServerSubLevelContainer.java:90)
	at net.minecraft.server.level.ServerLevel.handler$eng000$sable$tickPlotContainer(ServerLevel.java:13023)
	at net.minecraft.server.level.ServerLevel.tick(ServerLevel.java)
	at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1037)
	at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:917)

A related variant seen in the same session (index looks like -1 cast to an unsigned 64-bit value, 18446744073709551615), same physics tick call path:

java.lang.RuntimeException: Rapier native panic: index out of bounds: the len is 8 but the index is 18446744073709551615
	at dev.ryanhcode.sable.physics.impl.rapier.Rapier3D.step(Native Method)
	at dev.ryanhcode.sable.physics.impl.rapier.RapierPhysicsPipeline.physicsTick(RapierPhysicsPipeline.java:159)
	...

Suspected cause (not confirmed, just an observation)

The panic index (8, matching array length 8) suggests a fixed-size collider/body-part array for the player ragdoll skeleton being indexed one past its bound. This only happens with a TACZ weapon equipped, which renders as an extra GeckoLib-driven attachment on the player's hand — my guess is that this attachment ends up being counted as an extra ragdoll "part" that isn't accounted for in the fixed-size array, but I don't know the Sable/Rapier internals well enough to confirm. Flagging it in case it's useful — could also be a TACZ-side rendering/animation quirk feeding Sable bad data.

Environment

• Minecraft: 1.21.1
• NeoForge: 21.1.228
• Java: 21.0.3 (Microsoft build)
• Sable: 2.0.2 (sable-neoforge-1.21.1-2.0.2.jar)
• sable_player_ragdoll: 0.7.0
• sablephysicscompat: 1.3.0
• TACZ: 1.1.8-hotfix-r6
• tacz_aero_compat: 1.8.0

Additional notes

• Not reproduced with any non-TACZ held item so far.
• Also tried Sable 2.0.3 during troubleshooting — different but similarly-shaped crashes still occurred there (AbstractMethodError from an unrelated addon mod being out of date against 2.0.3's API, and a StackOverflowError from recursive logging in SubLevelPhysicsSystem.updatePose under load), so this doesn't look like a regression fixed by the 2.0.3 update.
• Happy to provide the full crash report / log file if needed.