Fix: no Go 1.15 binary for darwin/arm64 on Apple M1

If you use an Apple Silicon (M1) Mac, you will hit an issue when downloading Go 1.15 or earlier via the dl tool.

Here is 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

Note: You need a recent Go (1.22+) installed first.

Below are the steps showing how this was found.

Try to install in the usual way

I have a MacBook Pro with an M1 chip (arm64):

$ uname -m
arm64
About this Mac

About this Mac

The page “Managing Go installations” describes installing multiple Go versions. The normal steps for Go 1.15:

  1. Install the go1.15 helper into $GOBIN:

    $ go install golang.org/dl/go1.15@latest
$ ls "$(go env GOBIN)" | grep go1.15
go1.15

  2. Download the binary:

    $ go1.15 download
go1.15: download failed: no binary release of go1.15 for darwin/arm64 at https://dl.google.com/go/go1.15.darwin-arm64.tar.gz

I opened an issue: “dl: failed to install Go 1.15 on darwin/arm64”. A maintainer replied it would not be fixed because Go 1.15 is unsupported. I needed a workaround.

The Go team states that any Go program you can compile for amd64 should also work on Arm. So we can use the amd64 binary.

Workaround by modifying the dl source

I cloned the dl repo and found that versionArchiveURL builds the download URL.

Adding:

if goos == "darwin" && runtime.GOARCH == "arm64" {
if strings.HasPrefix(version, "go1.15") {
		arch = "amd64"
	}
}

makes it fall back to the amd64 archive.

Full adjusted function:

// versionArchiveURL returns the zip or tar.gz URL of the given Go version.
func versionArchiveURL(version string) string {
	goos := getOS()
	ext := ".tar.gz"
	if goos == "windows" {
		ext = ".zip"
	}
	arch := runtime.GOARCH
	if goos == "linux" && runtime.GOARCH == "arm" {
		arch = "armv6l"
	}
	if goos == "darwin" && runtime.GOARCH == "arm64" {
	    if strings.HasPrefix(version, "go1.15") {
			arch = "amd64"
	    }
	}
	return "https://dl.google.com/go/" + version + "." + goos + "-" + arch + ext
}

Build and run:

$ cd go1.15
$ go build
$ ./go1.15
go1.15: not downloaded. Run 'go1.15 download' to install ...
$ ./go1.15 download
... downloads ...
$ ./go1.15 version
go version go1.15 darwin/amd64

This works, but patching source is cumbersome. A simpler approach exists.

Better approach: set GOARCH

Try:

$ GOARCH=amd64; go install golang.org/dl/go1.15@latest
go: cannot install cross-compiled binaries when GOBIN is set

That fails due to a known issue: “cmd/go: allow installing cross-compiled binaries when GOBIN is set”.

Final solution

Use go run with GOARCH to download, then go install normally:

$ 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

Success.

You can repeat this for earlier versions (1.14, 1.13, 1.12, …) that lack native arm64 binaries:

GOARCH=amd64; go run golang.org/dl/go1.14@latest download
go install golang.org/dl/go1.14@latest
go1.14 version
go  arm64  macos 

See also