Summary
In this appendix, we installed our own build of Go from the source code, which means we can easily use the hg command to keep our installation up to date, or to test our beta features before they are released. It's also nice to have the entire Go language code for us to browse on those lonely nights by the fire.
You learned about the GOPATH environment variable, and discovered a common practice of keeping one value for all projects. This approach dramatically simplifies working on Go projects, where otherwise you would likely continue to encounter tricky failures.
We discovered how the Go toolset can really help us to produce high quality, community-standards-compliant code that any other programmer could pick up and work on with little to no additional learning. And more importantly, we looked at how automating the use of these tools means we can truly get down to the business of writing applications and solving problems, which is all that developers really want to do.