FYI - the recently introduced API change in LuaLanes/lanes@bfdc7a9 will break collection of worker results in multithreading.lua. Quote from referenced lanes commit:
Change lane:join() return values
- when no error is raised in the lane, lane:join() now precedes the lane returned values with true
Changing local _, ok, worker_results = assert(worker:join()) to local _, _, ok, worker_results = assert(worker:join()) in line 93 of multithreading.lua fixes the issue. I suggest to add some kind of version checking around this line of code with lanes.ABOUT.version.