latest with caching

Makefile

@@ -44,9 +44,9 @@ mfer.cmd: $(SOURCEFILES) mfer/mf.pb.go
 	cd cmd/mfer && go build -tags urfave_cli_no_docs -o ../../mfer.cmd $(GOFLAGS) .
 
 clean:
-	rm -rfv mfer/*.pb.go mfer.cmd cmd/mfer/mfer
+	rm -rfv mfer/*.pb.go mfer.cmd cmd/mfer/mfer *.dockerimage
 
-fmt:
+fmt: mfer/mf.pb.go
 	gofumpt -l -w mfer internal cmd
 	golangci-lint run --fix
 	-prettier -w *.json
@@ -56,9 +56,9 @@ lint:
 	golangci-lint run
 	sh -c 'test -z "$$(gofmt -l .)"'
 
-docker: sneak-mfer.$(ARCH).docker.tzst
+docker: sneak-mfer.$(ARCH).tzst.dockerimage
 
-sneak-mfer.$(ARCH).docker.tzst: $(SOURCEFILES) vendor.tar
+sneak-mfer.$(ARCH).tzst.dockerimage: $(SOURCEFILES) vendor.tzst modcache.tzst
 	docker build --progress plain --build-arg GITREV=$(GITREV_BUILD) -t sneak/mfer .
 	docker save sneak/mfer | pv | zstdmt -19 > $@
 	du -sh $@
@@ -67,7 +67,16 @@ godoc:
 	open http://127.0.0.1:6060
 	godoc -http=:6060
 
-vendor.tar: go.mod go.sum
+vendor.tzst: go.mod go.sum
+	go mod tidy
 	go mod vendor
-	tar -c vendor > $@
+	cd vendor && tar -c . | pv | zstdmt -19 > $(PWD)/$@.tmp
 	rm -rf vendor
+	mv $@.tmp $@
+
+modcache.tzst: go.mod go.sum
+	go mod tidy
+	cd $(HOME)/go/pkg && chmod -R u+rw . && rm -rf mod sumdb
+	go mod download -x
+	cd $(shell go env GOMODCACHE) && tar -c . | pv | zstdmt -19 > $(PWD)/$@.tmp
+	mv $@.tmp $@