The reason why i use pos.findClosestByRange, but saving is better.

Hmm my script runs fine, but uses a different way to build:

var target = creep.pos.findClosestByRange(FIND_CONSTRUCTION_SITES);
if(target != null) {
 if(creep.build(target) == ERR_NOT_IN_RANGE) {
 creep.moveTo(target);
 }
 }

with my beginners experience: Shouldnt your code have no spaces? -> conSite [0] -> conSite[0] ?

Edit: Ah excuse me

Nice, will try this to recreate it on RaspberryPi. Thanks for posting

update1: Raspbian doesnt support steam's architecture, retry with just debian.