Comment 4 for bug 1209044

Um, the code to pass all flags to plugins hasn't landed yet.

The real cause of the error is as follows: juju considers all executables starting with juju- in the path to be a plugin. When juju help plugins is run, it invokes all juju-* executables with --description. In this case, juju-admin and juju-log belong to pyjuju. They are not juju-core plugins so don't understand the --description argument.