Here's another one when bootstrapping foreman on up to date Debian stretch plus https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions (because of #20232) fails.

Following https://www.theforeman.org/contribute.html

bundle exec bin/rake db:seed

gives

2017-07-22T00:35:07 [app] [D] Setting current user thread-local variable to foreman_admin
rake aborted!
Unable to create anonymous admin user: Auth source can't be blank
/home/agx/foreman/db/seeds.d/04-admin.rb:14:in `block in <top (required)>'
/home/agx/foreman/vendor/gems/ruby/2.3.0/gems/audited-4.5.0/lib/audited/auditor.rb:283:in `without_auditing'
/home/agx/foreman/db/seeds.d/04-admin.rb:9:in `<top (required)>'
/home/agx/foreman/db/seeds.rb:46:in `block in <top (required)>'
/home/agx/foreman/db/seeds.rb:36:in `each'
/home/agx/foreman/db/seeds.rb:36:in `<top (required)>'
/home/agx/foreman/vendor/gems/ruby/2.3.0/gems/railties-4.2.9/lib/rails/engine.rb:547:in `load_seed'
-e:1:in `<main>'
Tasks: TOP => db:seed
(See full trace by running task with --trace)