juju fails to destroy environment due to missing configuration key

[Dave Cheney]

ubuntu@winton-02:~/src/launchpad.net/juju-core$ juju destroy-environment -y local
ERROR empty apt-ftp-proxy in environment configuration
ubuntu@winton-02:~/src/launchpad.net/juju-core$ echo $?
1

An environment I bootstrapped on Friday with 1.15.7.1 could not be destroyed with Mondays 1.17.6.1

[Dave Cheney (dave-cheney)]

Bumping to critical. --force doesn't work either

ubuntu@winton-02:~/src/launchpad.net/juju-core$ juju destroy-environment -y local --force
ERROR empty apt-ftp-proxy in environment configuration
ubuntu@winton-02:~/src/launchpad.net/juju-core$ echo $?
1

[Tim Penhey (thumper)]

Sorry, all my fault, but I'm doing this to fix the incompatibility the other way.

Only environments created from trunk have this issue, all releases are fine. Not going to fix this.