sable_tracking_points.dat growing abnormally large

[midshadow]

Context

Summary

Server crashes with java.lang.OutOfMemoryError: Java heap space while loading Sable tracking-point saved data on NeoForge 1.21.1.

Crash date/time

• 2026-06-28 01:52:03 (server local time)

Environment

• Minecraft: 1.21.1
• Loader: NeoForge 21.1.234
• Sable: 2.0.3 (sable-neoforge-1.21.1-2.0.3.jar)
• Java: Eclipse Adoptium 25.0.3
• JVM flags: -XX:+UseZGC -Xms16G -Xmx16G
• OS: Linux (Unraid kernel 6.6.78-Unraid)

Error

Exception in server tick loop
java.lang.OutOfMemoryError: Java heap space

Key stack trace path

• net.minecraft.nbt.NbtIo.readCompressed
• net.minecraft.world.level.storage.DimensionDataStorage.readTagFromDisk
• net.minecraft.world.level.storage.DimensionDataStorage.computeIfAbsent
• dev.ryanhcode.sable.sublevel.tracking_points.SubLevelTrackingPointSavedData.getOrLoad(SubLevelTrackingPointSavedData.java:45)

Evidence of oversized Sable saved-data files

From world root (find ... | sort -nr | head), top files were:

• 456395445 ./data/sable_tracking_points.dat (~435 MB)
• 169387711 ./data/tmp_sable_tracking_points.dat (~161 MB)

Other files were normal size by comparison (mostly KB/low MB).

Repro behavior

• Server crashes during startup/tick with OOM before players are online (Player Count: 0 in report).
• Crash consistently points to Sable tracking-point saved data load.

Temporary workaround that restores boot

1. Stop server.
2. Move these files out of world/data/:
   • sable_tracking_points.dat
   • tmp_sable_tracking_points.dat
3. Restart server.

Server boots after quarantining those files.

Notes

• This appears to be runaway growth and/or malformed NBT in Sable tracking-point persisted data.
• I can provide the full crash report and quarantined .dat files if useful.

Crash Report

https://mclo.gs/VmTvPMc