# cannot use relative path in GOROOT, otherwise 6g not found. For example,# export GOROOT=../go (=> 6g not found)# it is also not allowed to use relative path in GOPATHexport GOROOT=$(realpath ../go)export GOPATH=$(realpath .)export PATH:=$(GOROOT)/bin:$(GOPATH)/bin:$(PATH)INPUT=abc
default:fmt
@go run demo.go -input=$(INPUT)fmt:
@go fmt demo.go