Context: I was travelling down a river on a raft, to new areas I haven't been to yet, while simultaneously creating a map from it using the cartographer mod (unrelated to bug).
And then my game crashed and I got this error:
AsyncErr: Lua: Runtime error from mod 'rp_mobs_mobs' in callback luaentity_Activate(): /usr/share/minetest/builtin/common/misc_helpers.lua:418: attempt to index local 'pos' (a nil value)
stack traceback:
/usr/share/minetest/builtin/common/misc_helpers.lua:418: in function 'pos_to_string'
/home/user/.minetest/games/repixture/mods/rp_mobs/api.lua:455: in function 'init_mob'
...st/games/repixture/mods/rp_mobs_mobs/mobs/mineturtle.lua:197: in function <...st/games/repixture/mods/rp_mobs_mobs/mobs/mineturtle.lua:196>
I'm not sure what caused it, maybe it spawned, became too far away from me and it ran the function when it isn't loaded anymore or something.