-If you have just untarred a binary Go distribution, you need to set
-the environment variable $GOROOT to the full path of the go
-directory (the one containing this file). You can omit the
-variable if you unpack it into /usr/local/go, or if you rebuild
-from sources by running all.bash (see doc/install-source.html).
-You should also add the Go binary directory $GOROOT/bin
-to your shell's path.