force exported makefile variables to be exported in shell

Makefile

@@ -118,15 +118,15 @@ install-cross-build-tools:
 # https://github.com/wangyoucao577/go-release-action/blob/v1.40/action.yml#L109
 GOARCH := $(INPUT_GOARCH)
 
+
 .PHONY: pre-build
 pre-build: generate install-cross-build-tools
-	export CGO_ENABLED=1
-	export CGO_FLAGS="-O2 -D__BLST_PORTABLE__"
-	export GOARCH=$(GOARCH)
+	echo 'export CGO_ENABLED=1'
+	echo 'export CGO_FLAGS="-O2 -D__BLST_PORTABLE__"'
 	if [ "$(GOARCH)" = "arm64" ] ; then \
-		export CC=aarch64-linux-gnu-gcc ; \
+		echo 'export CC=aarch64-linux-gnu-gcc' ; \
 	elif [ "$(GOARCH)" = "amd64" ] ; then \
-		export CC=x86_64-linux-gnu-gcc ; \
+		echo 'export CC=x86_64-linux-gnu-gcc' ; \
 	else \
 		echo "arch target" $(GOARCH) "is not supported" ; \
 	fi