Handling active dependencies in Go

[William Reade]

On Mon, 2012-12-17 at 14:03 +0400, John Arbash Meinel wrote:
> The primary underlying issue we are trying to solve is that we want to
> make sure that juju-core's trunk branch always builds and passes its
> test suite. So that people have a known-working reference when
> developing their own code.

There's a (E) that I only just thought of, that's already used for
thirdparty/pbkdf2. I don't know the history, but ISTM possible that we
have already standardized on the "if the API's stable, use an external
import; otherwise just copy it in" strategy.

This kinda ugly, and wastes server space (oh noes), but might actually
be the Simplest Thing here: goose can develop as wildly as necessary,
and changes can feed through to juju-core as needed for the openstack
provider; once goose stabilizes, juju-core can switch to using versioned
URLs (as it does for mgo today).

Crack?

(FWIW, I like Kapil's suggestion most of all, but (E) above requires
zero extra tooling and STM to involve an absolute minimum of busywork on
API change.)

Cheers
William