So, about 80% of my townies are on a death march between a market and barrels, carrying iron back and forth endlessly. They're all going to die doing exactly that. How does an infinite loop happen in towns?
It probably happend because of the bug that you can remove offered items after you made the trade in the trading screen. To stop the loop you need to kill the caravan. Pause the game and around him add fluids
Disabled trading on all groups and waited for the guy to leave. Built a signpost in commemoration of the thousands of townie-hours lost in a loop. Never forget.