update building script

Dockerfile

@@ -45,7 +45,7 @@ ENV ANDROID_NDK_URL=https://dl.google.com/android/repository/android-ndk-r20-lin
 
 ENV LIBPCAP_URL=https://www.tcpdump.org/release/libpcap-1.9.0.tar.gz
 
-ENV GO_TARBALL=https://dl.google.com/go/go1.12.8.linux-amd64.tar.gz
+ENV GO_TARBALL=https://dl.google.com/go/go1.12.9.linux-amd64.tar.gz
 
 # Android toolchain
 RUN wget --quiet -O /opt/android-ndk.zip $ANDROID_NDK_URL

Makefile

@@ -9,6 +9,10 @@ GH_OWNER            ?= malfunkt
 GH_REPO             ?= arpfox
 GH_ACCESS_TOKEN     ?=
 
+GO111MODULE         ?= on
+
+export GO111MODULE
+
 define docker-run
 	docker run --rm \
 		-v $$PWD/$(BUILD_OUTPUT_DIR):/go/src/$(BUILD_PATH)/$(BUILD_OUTPUT_DIR) \
@@ -17,11 +21,11 @@ define docker-run
 		go build $(BUILD_FLAGS) -o $(BUILD_OUTPUT_DIR)/$(BIN_PREFIX)_$(2) $(BUILD_PATH)
 endef
 
+all: build-all
+
 build: modules
 	go build $(BUILD_FLAGS) -o arpfox github.com/malfunkt/arpfox
 
-all: docker-build
-
 build-all: modules docker-builder clean
 	mkdir -p $(BUILD_OUTPUT_DIR) && \
 	parallel -v --halt now,fail=1 $(MAKE) ::: \
@@ -89,7 +93,7 @@ docker-builder:
 	docker build -t $(DOCKER_IMAGE) .
 
 modules:
-	GO111MODULE=on go mod vendor
+	go mod vendor
 
 clean:
 	rm -f *.db && \