Probably the issue with garden itself, not the cli tools, yet I don't see where to report that, so here it goes,
Running a test deploy (calendula), toying with it and then trying to clean it up, the garden falls over with the error, possibly due to ignored "allow emails from $app?" message,
$ garden delete eijeijei
Deleting 'eijeijei'
Deleting a project will stop your current application and remove your data permanently. This cannot be undone!
If you delete a project, its name will be available to anyone else again.
If you want to delete project eijeijei, confirm by typing the project's name and pressing 'Enter':
eijeijei
java.lang.IllegalStateException: :db.error/unique-conflict Unique conflict: :notification/project+email, value: [nil "[email protected]"] already held by: 17592186052955 asserted for: 17592186053077