[0.17.45]Game crash in heavy mode

[Muppet9010]

I was testing a modded game and while in Editor mod with the Time Usage statistsics up I ran heavy mode and the game crashed. I've attached the logs, but had done a lot of messing around in the map and so can't reproduce it from the save.

The save can be made to fail the heavy checks via certain player actions, but this doesn't reproduce the game crash.

[Rseding91]

Thanks for the report. This is the same crash as 71494

You mentioned you could make heavy mode fail through some specific actions - what are those?

[Muppet9010]

by fail I mean fail a CRC check and show a desync.

Glad they are the same issue. I was trying to recreate the desync experienced in the MP game before the save crashing covered in the other bug when this crash in heavy mode occurred.

I was testing around the Will-o'-the-Wisps updated mod: https://mods.factorio.com/mod/Will-o-th ... 000c58735d
With respecting to creating the below:

I setup a test map with some biters vs wisps in heavy tress. Set so biters and wisps fight. I left it running with heavy-mode turned on to check for desync risk and got the below issue to occur.
https://www.dropbox.com/s/oca2imquotn5m ... s.zip?dl=0
This is the dump from heavy-mode (game state). If you use a text comparison tool (beyond compare) on to the 2 files you will see that there are different numbers and types of wisps occurring.

I did this as we had odd issues with desyncs in an MP game the other night.

[Rseding91]

Do you have any save file that reliably desyncs when run in heavy mode?

[Muppet9010]

no, but from looking at the deync report, heavy mode dumps, mod code and speaking to the mod author we have identified a local variable that affects the game state. So hopefully it it this causing the issues.
This local variable affects the chance and location of entity creation, all be it with a low math.random() probability chance.
In the desync report (large MP game) there was variation in the Factorio random number generator entries in script.dat. In the heavy mode dumps I could see variation in the types of entities his mod had created.