Installing Google Go

Environment variables

The Go compilation environment depends on three environment variables that you should set in your .bashrc or equivalent, plus one optional variable:

$GOROOT

The root of the Go tree. Typically this is $HOME/go but it can be any directory.

$GOOS and $GOARCH

The name of the target operating system and compilation architecture. Choices for $GOOS are linux, freebsd, darwin (Mac OS X 10.5 or 10.6), and nacl (Native Client, an incomplete port). Choices for $GOARCH are amd64 (64-bit x86, the most mature port), 386 (32-bit x86), and arm (32-bit ARM, an incomplete port). The valid combinations of $GOOS and $GOARCH are:

 

	$GOOS	$GOARCH
	darwin	386
	darwin	amd64
	freebsd	386
	freebsd	amd64
	linux	386
	linux	amd64
	linux	arm
	nacl	386

 

$GOBIN (optional)

The location where binaries will be installed. The default is $HOME/bin. After installing, you will want to arrange to add this directory to your $PATH, so you can use the tools.

$GOARM (optional, arm, default=6)

The ARM architecture version the runtime libraries should target. ARMv6 cores have more efficient synchronization primitives. Setting $GOARM to 5 will compile the runtime libraries using just SWP instructions that work on older architectures as well. Running v6 code on an older core will cause an illegal instruction trap.

Note that $GOARCH and $GOOS identify the target environment, not the environment you are running on. In effect, you are always cross-compiling.

Set these variables in your .bashrc. For example:

export GOROOT=$HOME/go
export GOARCH=amd64
export GOOS=linux

Double-check them by listing your environment.

$ env | grep '^GO'

I had to download mercurial-1.4.3  and the
latest Python to get working.

Make sure the $GOROOT directory does not exist or is empty. Then check out the repository:

$ hg clone -r release https://go.googlecode.com/hg/ $GOROOT

To build the Go distribution, run

$ cd $GOROOT/src $ ./all.bash

If all goes well, it will finish by printing

--- cd ../test N known bugs; 0 unexpected bugs

N was a happy 0 on my intraback pc.

Keeping up with releases

New releases are announced on the Go Nuts mailing list. To update an existing tree to the latest release, you can run:

$ cd $GOROOT/src
$ hg pull
$ hg update release
$ ./all.bash