Error on line 415: Attempt to index local 'lookuptable' (a nil value)

[tschlienger]

Hey there, I'm currently trying to make use of your pretty adavanced program on FTB Revelation 3.4.0 using Minecraft 1.12.2. For some reason your script always fails at the same spot for me: At first everything works well, the defined tree farm is built using dirt, saplings and torches, but after a little while - usually after returning to the chests - it always stops at the exact same spot and throws an error on line 415 of the worker script: Attempt to index local 'lookuptable' (a nil value). Do you have any idea why this keeps happening?

[tschlienger]

After multiple tries I can now say that the turtle will always stop on the same line of blocks (Marked by stone on screenshot), not the exact same block.

[PPakalns]

Hi, thanks for using this fun project of mine.

There could be multiple possible reasons so I would need additional information about your setup.

Are there enough fuel items in the fuel chest?
When program is initialized, does the robot correctly retrieve all the necessary items from all the chests?
When you initialize a new robot, do not provide a lot of fuel so that it needs to refuel after some time, does it correctly go to fuel chest or does it simply go to your marked location and crashes.

I remember that I implemented some functionality, if there is not enough fuel, then it would go to similar location as you have marked out for manual refueling, but that functionality probably was not very well tested.

Additional issue could be due to chunk loading reloading, as this program doesn't use gps module, when chunks are unloaded, loaded, the robot position could de-synchronize by one block, but this issue doesn't seem to be caused by that.

[tschlienger]

Thanks for your reply. There's enough fuel in the chest and turtles, and the program doesn't fail when going through all the chests, comparing its items and refilling itself.

I had a look at your code myself and figured out it COULD have something to do with your if-statement on line 396 inside worker.lua. The script crashes because it attempts to call lookuptable for each item slot, comparing it to arrays defined in your script header. This will be executed if robot.location is bigger than 0, although robot.location 6 - called robot.home (seems to be the coordinates where my turtle crashes) - doesn't have such an array, which results in the if-statement on line 400 not altering the local lookuptable and therefore returning nil. I'm not sure if that's actually the issue, but either adding a "and robot.location<6" to the if-statement on line 396 or creating an empty array called Home and adding another elseif for location 6 after line 409 solved the issue for me. Could this have something to do with your mentioned and not well tested "manual refueling" spot?

Now though, even though the program seems to work fine, sometimes (mostly, but not always in front of leaves or woodblocks) the turtle will suddenly stop, printing endless "A* Recalculating" to the terminal. I'm not sure if that's caused by my workaround or by a bug in the program itself.