we do actually want to cache arudino cores

bin/kaleidoscope-builder

@@ -149,7 +149,7 @@ build_paths() {
 
 	: "${BUILD_PATH:=${KALEIDOSCOPE_BUILD_PATH}/${SKETCH_BUILD_DIR}}"
 	: "${OUTPUT_PATH:=${KALEIDOSCOPE_OUTPUT_PATH}/${SKETCH_OUTPUT_DIR}}"
-
+        : "${CORE_CACHE_PATH:=${KALEIDOSCOPE_TEMP_PATH}/arduino-cores}"
 
 
 	: "${LIB_PROPERTIES_PATH:="../.."}"
@@ -305,6 +305,7 @@ compile() {
 		--libraries "${KALEIDOSCOPE_DIR}/.." \
 		--build-path "${BUILD_PATH}" \
 		--output-dir "${OUTPUT_PATH}" \
+	        --build-cache-path "${CORE_CACHE_PATH}" \
 		--build-properties "compiler.path=${COMPILER_PATH}/" \
 		--build-properties "compiler.c.cmd=${_CMD_CC}" \
 		--build-properties "compiler.cpp.cmd=${_CMD_CXX}" \