6g: No such file or directory - Building Go packages with `gomake` on Snow Leopard

I have two .go files, numbers.go and numbers_test.go and I want to build and execute the tests as per the creating a new package tutorial (scroll down for details on the files.) All files are in the same directory.

When I navigate to that directory in Terminal and type gomake I get this:

6g  -o _go_.6 numbers.go
make: 6g: No such file or directory
make: *** [_go_.6] Error 1

This error is saying that it cannot find numbers.go. If I manually execute this line (without moving directory):

6g  -o _go_.6 numbers.go

it successfully creates the _go_.6 file. So why can't gomake find the file?

Here are the files I am using:

numbers.go l开发者_JAVA百科ooks like this:

package numbers

func Double(i int) int {
  return i * 2
}

numbers_test.go looks like this:

package numbers

import (
    "testing"
)

type doubleTest struct {
    in, out int
}

var doubleTests = []doubleTest{
    doubleTest{1, 2},
    doubleTest{2, 4},
    doubleTest{-5, -10},
}

func TestDouble(t *testing.T) {
    for _, dt := range doubleTests {
        v := Double(dt.in)
        if v != dt.out {
            t.Errorf("Double(%d) = %d, want %d.", dt.in, v, dt.out)
        }
    }
}

and finally, my Makefile looks like this:

include $(GOROOT)/src/Make.inc

TARG=numbers
GOFILES=\
    numbers.go

include $(GOROOT)/src/Make.pkg

The error doesn't say that it can't find numbers.go - it's saying that it can't find 6g. In your Makefile, try putting the path to 6g in your PATH, as well as any other Go-specific environment variables.