error install google go

error install google go

venj@iMacBook ~ » brew update
From http://github.com/mxcl/homebrew
 * branch            master     -> FETCH_HEAD
Already up-to-date.
venj@iMacBook ~ » brew install -v go
/usr/local/bin/hg
==> Cloning http://go.googlecode.com/hg/
Updating /Users/venj/Library/Caches/Homebrew/go--hg
hg pull
pulling from http://go.googlecode.com/hg/
searching for changes
no changes found
hg update
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
==> Checking out revision release
hg archive -y -r release -t files /private/tmp/homebrew-go-HEAD-vOHT
==> ./all.bash
./all.bash 
$GOROOT is not set correctly or not exported: /usr/local/Cellar/go
==> Exit Status: 1
http://github.com/mxcl/homebrew/blob/master/Library/Formula/go.rb#L25
==> Environment
HOMEBREW_VERSION: 0.8
HEAD: e4a7eeecd751a05a2632be2cbc081a2c7bb589de
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
HOMEBREW_REPOSITORY: /usr/local
HOMEBREW_LIBRARY_PATH: /usr/local/Library/Homebrew
Hardware: dual-core 64-bit penryn
OS X: 10.6.7
Kernel Architecture: i386
Ruby: 1.8.7-174
/usr/bin/ruby => /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
Xcode: 4.0
GCC-4.0: build 5494 
GCC-4.2: build 5666 
LLVM: build 2335 
MacPorts or Fink? false
X11 installed? true
==> Build Flags
CC: /usr/bin/cc => /usr/llvm-gcc-4.2/bin/llvm-gcc-4.2
CXX: /usr/bin/c++ => /usr/bin/c++-4.2
LD: /usr/bin/cc => /usr/llvm-gcc-4.2/bin/llvm-gcc-4.2
CFLAGS: -O3 -march=core2 -msse4.1 -w -pipe
CXXFLAGS: -O3 -march=core2 -msse4.1 -w -pipe

Error: Failed executing: ./all.bash 
Please report this bug: https://github.com/mxcl/homebrew/wiki/new-issue

Also try:
  `brew doctor` to check your setup for common problems.
  `brew missing` to check installed packages for missing deps.
venj@iMacBook ~ » brew doctor
Your OS X is ripe for brewing.
Any troubles you may be experiencing are likely purely psychosomatic.