Juju 2.x upgrade [ppa] doesn't show a workable way to downgrade to 1.25

[Bryan Quigley]

I'm running Juju on Trusty with the Juju Stable PPA (https://launchpad.net/~juju/+archive/ubuntu/stable).

Recently Juju 2.x replaced the Juju 1.25 version (automatic updates) and had this to say on first run:
ubuntu@trusty-admin:~$ juju status
    Welcome to Juju 2.0.0. If you meant to use Juju 1.x you can continue using it
    with the command juju-1 e.g. 'juju-1 switch'.
    See https://jujucharms.com/docs/stable/introducing-2 for more details.

Since Juju 2 is being run for the first time, downloading latest cloud information.
Fetching latest public cloud list...
Your list of public clouds is up to date, see `juju clouds`.
ERROR No model in focus.

Please use "juju models" to see models available to you.
You can set current model by running "juju switch"
or specify any other model on the command line using the "-m" flag."

The juju-1 switch command doesn't exist:
ubuntu@trusty-admin:~$ juju-1 switch
juju-1: command not found

To go back to juju-1.25 I had to remove juju juju-core juju-2.0 and reinstall juju-core.

[Bryan Quigley (bryanquigley)]

GH - https://github.com/juju/docs/issues/1470

[Nicholas Skaggs (nskaggs)]

On trusty, the juju packages use update-alternatives. However, the package in the ppa doesn't support this properly. See bug 1633593

[Nicholas Skaggs (nskaggs)]

@Anastasia, I'm not sure how you feel the juju-1-switch command should be addressed. This bug is mostly a dupe of bug 1633593, apart from that.

[Curtis Hovey (sinzui)]

The install looks like this
    http://paste.ubuntu.com/23324765/

[Nicholas Skaggs (nskaggs)]

Note, I filed bug 1634405 for the juju-1 switch verbiage which is REALLY confusing in this case.