Instructions for working on Packer

Makefile

+all:
+	@mkdir -p bin/
+	go build -o bin/packer packer/bin-packer
+
+.PHONY: all

README.md

@@ -7,4 +7,14 @@ machine images to launch into any environment, such as VirtualBox, VMware,
 Amazon EC2, etc. Because this build process is automated, you can develop in
 VirtualBox, then deploy to EC2 with an identical image.
 
+## Developing Packer
 
+If you wish to work on Packer itself, you'll first need [Go](http://golang.org)
+installed. Next, clone this repository and source "setup.sh" in your shell. This
+will set up the environmental variables properly to work on Packer. After
+that, just run `make`. Commands:
+
+```
+$ source setup.sh
+$ make
+```

setup.sh

+#!/usr/bin/env bash
+
+# Get the full path to the directory where this script is, because
+# GOPATH prefers full paths.
+SOURCE="${BASH_SOURCE[0]}"
+while [ -h "$SOURCE" ] ; do SOURCE="$(readlink "$SOURCE")"; done
+DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
+
+# Setup our GOPATH
+echo "Setting GOPATH to: ${DIR}"
+export GOPATH="${DIR}"