Google App Engine: request.BasicAuth undefined (type *http.Request has no field or method BasicAuth)

I'm trying to deploy a go app to Google App Engine but compilation is failing because of this error.

request.BasicAuth undefined (type *http.Request has no field or method BasicAuth)

I figured this error meant that my google app engine installation was not the latest one so I updated it and now running go_appengine/goapp version returns:

go version go1.4.1 (appengine-1.9.18) darwin/amd64

I can successfully serve my app but I keep getting this error when I try to deploy. What am I missing?

The Go AppEngine runtime environment uses Go version 1.2 as you can read it on the Go Runtime Environment page.

A beta version of 1.4 runtime version is available, you can read more about it here:

go1.4beta is now ready for testing

If you want to use the 1.4 beta runtime, you have to specify it in your app.yaml config file like this:

api_version: go1.4beta

Note that even though Go 1.4 is out (current version is 1.4.2), the AppEngine runtime version of 1.4 is still not released.

Quoting the relevant part:

> Go 1.4 has not yet been released, so the go1.4beta runtime is built
from the release-branch.go1.4 of the core Go tree, and may be updated
as Go 1.4 approaches.

> We will not be providing a beta version of the Go 1.4 SDK. You should
use goapp deploy (or appcfg.py) from the normal Go App Engine SDK to
deploy your app.

> To use go1.4beta, update your app.yaml file to use the new api_version:

> api_version: go1.4beta

> After Go 1.4 is released it will become the basis for api_version
'go1', as normal, and 'go1.4beta' will be retired soon afterward. We
expect this to happen early next year.