I saw that there were circuit readers and writers added so I wanted to try them out, but I consistently crash every time I place a circuit reader next to a fluid depot (with the circle part adjacent to the depot).

Here's the crash log:

Error while running event Transport_Drones::on_tick (ID 0)
'count': real number expected got nil.
stack traceback:
Transport_Drones/script/depots/fluid_depot.lua:117: in function 'update_contents'
Transport_Drones/script/depots/fluid_depot.lua:138: in function 'update'
Transport_Drones/script/depot_common.lua:379: in function 'update_depots'
Transport_Drones/script/depot_common.lua:387: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>
stack traceback:
[C]: in function 'set_signal'
Transport_Drones/script/depots/fluid_depot.lua:117: in function 'update_contents'
Transport_Drones/script/depots/fluid_depot.lua:138: in function 'update'
Transport_Drones/script/depot_common.lua:379: in function 'update_depots'
Transport_Drones/script/depot_common.lua:387: in function 'handler'
core/lualib/event_handler.lua:47: in function <core/lualib/event_handler.lua:45>