How to cross-compile a Go program on macOS?

Hi everyone! I'm writing Go on macOS and want to build a binary for Linux and Windows to run on a server and share with colleagues. I tried simply running `go build`, but it creates an executable only for macOS. I read that Go has built-in support for cross-compilation, but I can't figure out how to do it correctly. Here's my simple code (main.go file): ```go package main import "fmt" func main() { fmt.Println("Hello, cross-compilation!") } ``` I tried: ```bash GOOS=linux GOARCH=amd64 go build main.go ``` But got an error: `cannot find package "main" in any of: ...` or a binary that doesn't run on Linux. What am I doing wrong? Do I need to install additional tools, like for CGo? I have macOS Big Sur, Go version 1.21. I'd be grateful.