How do you verify/debug a migration?

[arthens]

I'm having problems with a mod I'm using, and being a developer myself I thought I'd try to debug the issue (it's a reasonably popular mod and no one else reported it, so I suspect something might be off in my save/game).

The problem is quite simple: the mod has a .json migration because a few items got renamed from .14 to .15, but the migration isn't being ran or it doesn't work. When I load the save all those items get removed. All I can tell is that the game is at least loading the migration in memory because if I introduce a syntax error it complains and crashes. But how do I verify the that migration is actually being ran?

Any tip?

Thank you.

[arthens]

Found the problem. The migration file contained 4 json objects instead of 1. The game executed the first one and ignored the other 3. I'll report the problem to the developer.