start to cut down on vars exported into subshells now that builder is gone

etc/makefiles/sketch.mk

@@ -37,14 +37,14 @@ export FQBN := $(call _arduino_prop,build.fqbn)
 export BOOTLOADER_PATH := $(call _arduino_prop,runtime.platform.path)/bootloaders/$(call _arduino_prop,bootloader.file)
 
 # Find the path of the sketch file 
-export SKETCH_FILE_PATH := $(firstword $(foreach dir,$(sketch_dir_candidates),$(sketch_exists_p)))
+SKETCH_FILE_PATH := $(firstword $(foreach dir,$(sketch_dir_candidates),$(sketch_exists_p)))
 
 # We -could- check to see if sketch-dir is in git before running this command 
 # but since we'd just return an empty value in that case, why bother?
 export GIT_VERSION := $(shell git -C "$(sketch_dir)" describe --abbrev=6 --dirty --alway  2>/dev/null || echo 'unknown')
 
 
-export SKETCH_IDENTIFIER := $(shell echo "$${SKETCH_FILE_PATH}" | cksum | cut -d ' ' -f 1)-$(SKETCH_FILE_NAME)
+export SKETCH_IDENTIFIER := $(shell echo "${SKETCH_FILE_PATH}" | cksum | cut -d ' ' -f 1)-$(SKETCH_FILE_NAME)
 
 
 
@@ -53,17 +53,18 @@ export SKETCH_IDENTIFIER := $(shell echo "$${SKETCH_FILE_PATH}" | cksum | cut -d
 export KALEIDOSCOPE_TEMP_PATH ?= $(TMPDIR)/kaleidoscope-$(USER)
 export KALEIDOSCOPE_BUILD_PATH ?= $(KALEIDOSCOPE_TEMP_PATH)/build
 export KALEIDOSCOPE_OUTPUT_PATH ?= $(KALEIDOSCOPE_TEMP_PATH)/output
-export CORE_CACHE_PATH ?= $(KALEIDOSCOPE_TEMP_PATH)/arduino-cores
+
+CORE_CACHE_PATH ?= $(KALEIDOSCOPE_TEMP_PATH)/arduino-cores
 
 export BUILD_PATH ?= $(KALEIDOSCOPE_BUILD_PATH)/$(SKETCH_IDENTIFIER)
 export OUTPUT_PATH ?= $(KALEIDOSCOPE_OUTPUT_PATH)/$(SKETCH_IDENTIFIER)
 
 
-export OUTPUT_FILE_PREFIX 		:= $(SKETCH_BASE_NAME)-$(GIT_VERSION)
-export HEX_FILE_PATH 			:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX).hex
-export HEX_FILE_WITH_BOOTLOADER_PATH 	:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX)-with-bootloader.hex
-export ELF_FILE_PATH 			:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX).elf
-export LIB_FILE_PATH 			:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX).a
+OUTPUT_FILE_PREFIX 		:= $(SKETCH_BASE_NAME)-$(GIT_VERSION)
+HEX_FILE_PATH 			:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX).hex
+HEX_FILE_WITH_BOOTLOADER_PATH 	:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX)-with-bootloader.hex
+ELF_FILE_PATH 			:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX).elf
+LIB_FILE_PATH 			:= $(OUTPUT_PATH)/$(OUTPUT_FILE_PREFIX).a
 
 
 KALEIDOSCOPE_BUNDLE_LIB_DIR := $(abspath (KALEIDOSCOPE_DIR)/..)