ROOT is defined automatically and not overridable. Remove the lines in the comments and docs

bin/kaleidoscope-builder

@@ -134,8 +134,8 @@ firmware_size () {
 
 find_sketch () {
     SKETCH="${SKETCH:-${DEFAULT_SKETCH}}"
-    if [ -z "${SKETCH}" ] || [ -z "${ROOT}" ]; then
-        echo "SKETCH and ROOT need to be set before including this file!" >&2
+    if [ -z "${SKETCH}" ]; then
+        echo "SKETCH needs to be set before including this file!" >&2
         exit 1
     fi
   

etc/kaleidoscope-builder.conf

@@ -1,6 +1,6 @@
 # -*- shell-script -*-
 
-## NEEDS: SKETCH, ROOT
+## NEEDS: SKETCH
 ## Should be included when the current directory is the dir of the Sketch.
 
 SKETCH="${SKETCH:-${DEFAULT_SKETCH}}"