# go build with -o and -buildmode=exe should on a non-main package should throw an error ! go build -buildmode=exe -o out$GOEXE not_main stderr '-buildmode=exe requires exactly one main package' ! exists out$GOEXE ! go build -buildmode=exe -o out$GOEXE main_one main_two stderr '-buildmode=exe requires exactly one main package' ! exists out$GOEXE -- not_main/not_main.go -- package not_main func F() {} -- main_one/main_one.go -- package main func main() {} -- main_two/main_two.go -- package main func main() {}