>>>>> "Sean" == Sean Conner <sean@conman.org> writes: Sean> The Lua call stack and C call stack are two separate things. Sean> The Lua VM does not use longjmp() to implement coroutines [a][d]. In 5.4, the VM recurses on the C stack, so it does indeed use longjmp as part of yield(). https://github.com/lua/lua/blob/1fb4d539254b67e7e35ed698250c66d1edff0e08/ldo.c#L729 -- Andrew.