Comment 1 for bug 862680

This causes juju to fail to wait for the entire environment to be shutdown because the initial terminate_instances does not return a list of shutting down instances.

$ juju -v destroy-environment
2011-09-29 18:32:08,229 DEBUG Initializing juju destroy-environment runtime
WARNING: this command will destroy the 'canonistack' environment (type: ec2).
This includes all machines, services, data, and other resources. Continue [y/N]y
2011-09-29 18:32:10,608 INFO Destroying environment 'canonistack' (type: ec2)...
2011-09-29 18:32:12,802 INFO Waiting on 0 EC2 instances to transition to terminated state, this may take a while
2011-09-29 18:32:13,169 DEBUG Deleted environment security group 'juju-canonistack'
2011-09-29 18:32:13,170 INFO 'destroy_environment' command finished successfully

With EC2 it would have waited for the 4 machines I had in the environment to terminate.