Not tried earlier versions, added this to a server and keep getting desyncs within about 60 seconds of a player joining.

A desync report sent to me by one of the players: https://overminddl1.com/Factorio/desyncs/desync-report-2019-04-28_19-48-51.zip

Adding Hive Mind desyncs, removing Hive Mind stops the desyncs, UC and TA remains the whole time.

Thanks for the report,

There is only a tiny difference in the CRC, something in random generator.

Does the desync happen if you save and load fresh with the mod enabled?
Does it happen everytime the mod is installed?

I thought I gleaned the same thing from the desync report as well but wasn't certain due to lack of tooling for them (I really need to get around to building 'something' for them...). Only tried it on the existing server thus far. The server was restarted a number of times both with and without the mod until it was finally found out that it was this mod that it was happening with. At no point did anyone join the hive mind team yet. Any time the server was loaded without this mod there were no desyncs after 5 minutes of waiting each time, and with this mod there was a desync within ~60 seconds each time. With it removed but all other mods still enabled the server has been running for almost 2 days now without a desync.

I'll see if I can rope someone in to trying a new map with the mod set and hive mind installed. The save it was installed in to is just entering blue science with a significant mod pack (AAI/Angels/Bobs/Clown/etc...) on a death world. I can grab one of the server saves if you want to see if you can test with it directly?

I think this is a save that was saved shortly after all the testing, so adding hive mind to it might replicate it.
https://overminddl1.com/Factorio/saves/OverGreg3-14g.zip (21 megs SHA1: 35df5e0f43b7b3e1d0c4095c39330ed14f4f84f6)

Does it happen for all players or a specific player?

Does it happen for all players or a specific player?

Was only testing with 1 other player. That player (that consistently desynced) was the GregoriusT player. I was hosting at the time (much easier to test mods out by just bringing up/down my own client and have him connect before I toss it on a server after testing is complete).

Is he on a different operating system? I have a suspicion that it could be related to square rooting returning or rounding slightly differently based on OS

Heh, actually in a weird coincidence we are both running Kubuntu, though different versions.

My uname-a is (yes I have a very old kernel, I can't upgrade it because of some hardware limitations just 'yet'): Linux overmind 4.4.0-140-generic #166-Ubuntu SMP Wed Nov 14 20:09:47 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

I'll see if I can get his too.

His is: Linux ZBOX 4.15.0-47-generic #50-Ubuntu SMP Wed Mar 13 10:44:52 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Well, thats a lot of mods, I can't even manage to get the game to load with my latest version of the mod installed.

Without the mod running, I found a desync just starting a new game, it could be that another mod is outputting the desync data, but that it is my mod that actions that bad data which causes the 'real' desync, things such as raising events at the wrong time, or somethign strange like that

I will have a new version out soon (I hope, loading with all your mods showed a lot of compatibility problems...), and in the meantime I will try to brainstorm where the root of the issue may lie

Without the mod running, I found a desync just starting a new game, it could be that another mod is outputting the desync data, but that it is my mod that actions that bad data which causes the 'real' desync, things such as raising events at the wrong time, or somethign strange like that

Very likely, a lot of modders don't really keep things up to standards and the game engine doesn't really encourage them to do so until someone reports it to them, so if you find what it is... :-)

I will have a new version out soon (I hope, loading with all your mods showed a lot of compatibility problems...), and in the meantime I will try to brainstorm where the root of the issue may lie

At least this was helpful in some way. ^.^