[CRUNCH] Fail gracefully when arvados repo doesn't exists
today we get
==> /etc/service/crunch-dispatch-jobs-0/log/main/current <== 2016-01-06_11:24:44.36262 /var/www/arvados-api/current/lib/crunch_dispatch.rb:34:in `initialize': undefined method `server_path' for nil:NilClass (NoMethodError) 2016-01-06_11:24:44.36266 from ./script/crunch-dispatch.rb:13:in `new' 2016-01-06_11:24:44.36267 from ./script/crunch-dispatch.rb:13:in `<main>'
the relevant part of the code is:
@arvados_repo_path = Repository.where(name: "arvados").first.server_path
This message is hard to debug.
we should be detecting that there is no arvados repository and include a link in the debug message to read further how to solve this like http://doc.arvados.org/install/create-standard-objects.html
this should also be the common practice for future versions of crunch