So back to my original question: how do you debug something like this? Even if I do set up a multiplayer game and reproduce the problem, how on earth do I track down the line of code that's doing something bad and causing the desync?

Yes, that's the mod, my bad :) I only have one report from one mutli-player user about the desync, but apparently it happens when a blueprint is placed during multiplayer with one of the poles. I'll follow up with them and ask what other mods they're using, although I suspect the list will be... len...

Thanks for the reply. I'm not using math.random(), and the mod is pretty simple. Anyone have suggestions for how to debug? I don't want to just stare at the code and randomly guess at what might be wrong.

A mod like this already exists, see https://mods.factorio.com/mods/SeelenJa ... T-DirtyOre. Looks like it was implemented in the ore, not the drill.

I've got a bug report from someone using my lighted electric poles mod that when the poles are used in a blueprint during a multiplayer game it results in a desync. They sent me a desync report, but I'm not familiar with how to interpret the report. I took a peek at log.txt and all it says is errors...

Ah yes, I see right at the top he's got a trigger_event list for supported poles that trigger the event getting fired. I'll hand-hack that to update it with my poles, make sure that works, then will reach out to the author and request an update.

Thanks for everyone's help!

Ah, that's yours! It's great, I used your approach as a base for what I'm working on. I've re-done my removal code again and it appears that robots are correctly cleaning things up now. Did you ever have trouble with FARL not placing your hidden light? FARL will place my poles, but not the light :( ...

I have the same flags in the lamp definition:

flags = {"placeable-off-grid", "not-on-map"},

What mod are you doing something similar in? Maybe if I compare the code I can see where I have some flag or something set differently.

Thanks for the reply. I spent some time this morning attempting to fix the deconstruction problem by swapping over to an area search. My new code, using Factorio stdlib, is as follows: local b = event.entity local X = b.position.x local Y = b.position.y local hidden_lights = Surface.find_all_entitie...

Found a documentation bug on http://afforess.github.io/Factorio-Stdl ... rface.html. The example for find_all_entities says final_all_entities instead.

I've got a mod up and running that adds lit versions of the four power poles (small, med, large, substation) to the game. It works great once the poles are placed, however during playtesting I discovered two intermittent issues: 1. The hidden light doesn't always get added when FARL places the pole[...