$ juju debug-hooks --help
usage: juju debug-hooks [-h] [-e ENVIRONMENT]
unit_name [hook_names [hook_names ...]]
unit_name Name of unit
hook_names Name of hook, defaults to all
-h, --help show this help message and exit
-e ENVIRONMENT, --environment ENVIRONMENT
juju environment to operate in.
I don't know what 'juju debug-hooks' does, and after running it with --help, I'm not any more enlightened. Would be great if it had a few words on what it does and why I might want to use it.