I didn't know that about Go, that's pretty cool! I assumed it was like Rust, where the compiler/toolchain makes builds on arbitrary specific platforms really easy to do, but where you still have to actually do those very narrow builds.
I think you may have misunderstood: each “go build” incantation lets you produce a single OS/arch binary, not a “fat binary”. So you make a build per OS/arch pair and distribute it.
> I assumed it was like Rust, where the compiler/toolchain makes builds on arbitrary specific platforms really easy to do, but where you still have to actually do those very narrow builds.