Makefile未设置GOOS环境变量

I write below Makefile to build Golang code for different platforms. (My OS is Windows 10 and run Makefile through command prompt)

GOCMD   =  go
GOBUILD =  $(GOCMD)  build
GOFILES =   $(wildcard *.go)
SONG_PATH =  ./song-service
SONG_PATH_OUTPOUT =  ./song-service/cmd
SONG_BINARY_NAME_LIN =  songservice_lin

song-build-lin:
    set GOOS=linux
    set GOARCH=amd64
    $(GOBUILD)  -o "$(SONG_PATH_OUTPOUT)/$(SONG_BINARY_NAME_LIN)" -v "$(SONG_PATH)/$(GOFILES)"

When I run make song-build-lin it runs without error but GOOS variable doesn't set. But when I run set GOOS=linux in command prompt directly it works!