1.20.1 server crash due to console spam - [Server thread/ERROR] [pneumaticcraft/]: SemiblockTracker: not overwriting existing semiblock at ServerLevel[world]

[b0bst3r]

Describe the bug

This was reported on the Benbenlaw discord - "as soon as a player joins the server, it crashes. even removing, or replacing all the blocks using amulet is not working. Issue first appeared on tuesday 5th on server restart. Loading an older Backup of the server still crashes the game."

The title of the report is "server crashing because of Pn crop support"

I will point the user who reported it to here for more information if you need it.

How to reproduce the bug

This I am unsure of as it's on someone elses server, I will however point them to this git.

Expected behavior

Report it once maybe and not crash the server with hundreds of lines in a second?

All the lines in the log appear to be within the same second and simply overloaded the server.

Additional details

Server crashed/froze due to hundreds of lines of spam.

Which Minecraft version are you using?

1.20

Which version of PneumaticCraft: Repressurized are you using?

pneumaticcraft 6.0.11+mc1.20.1

Crash log

https://gist.github.com/b0bst3r/8cda3cc0fbcf444784aed36019466785

[desht]

I don't see anything indicating an actual server crash here. The log messages are a symptom of whatever problem your server has, and there's no hard data here that they're the cause of the problem (not saying they're not related, but there's not enough info in the log file).

It happens when the crop support entity is added to the world, due to the chunk being loaded. At that point, a mapping is added from the blockpos it's in to the entity (which is what SemiblockTracker is for). But in this case, there's already a mapping for that blockpos, which should not happen, especially if the chunk is being loaded for the first time on the server. It means that there was previously a mapping, which wasn't cleared when the entity/chunk unloaded, as it should have been.

I can either suppress the error completely, or not at all. The error is logged separately for each blockpos that contains a crop support, and only once, when the entity is added to the world. So it's not a case of "spam", just a case of a player with a huge number of crop supports.

Is this a dedicated or integrated server?