If you are using an Apple Silicon M1 chip, then you may encounter an issue when downloading Go versions 1.15 or earlier via dl.
Here are the solution:
$ GOARCH=amd64; go run golang.org/dl/go1.15@latest download
$ go install golang.org/dl/go1.15@latest
$ go1.15 version
go version go1.15 darwin/amd64