Hi Matt, I add "-e to at the top file bash: #!/bin/bash -e" for all shell scripts under hooks. I will test it and talk with my manager before I check-in today. For unused hook hpcc-relation-changed, if I remove it 'juju charm proof' will report an info massage: "I: relation hpcc has no hooks". And I must keep 'hpcc' in "provider" field in metadata.yaml otherwise will get a warning. Thanks On Wed, Mar 5, 2014 at 2:55 PM, Xiaoming Wang