When running a rake task that includes the Katello::SubscriptionMailer, it fails with error:

RuntimeError (The Dynflow world was not initialized yet. If your plugin uses it, make sure to call Rails.application.dynflow.require! in some initializer)

Only seems to happen on nightly; not on devel boxes.

Steps to reproduce

# Import a manifest with at least one subscription that expires <180 days
# Attach that subscription to a host
# Run the Subscriptions - Entitlement Report (Monitor -> Report Templates) with Days from Now set appropriately
# Verify that the report shows that host and subscription
# In My Account -> Email Preferences, set up the Subscriptions Expiring Soon email and configure for Daily emails
# Run /usr/sbin/foreman-rake reports:daily

Expected: no output; if email is set up you are emailed the report
Actual: the error above

Alternate steps to reproduce (doesn't require a host/subscription)

In foreman-rake console, run

 include Katello::SubscriptionMailerHelper
 start_report_task(120)


Expected: return the job ID as a string
Actual: the error above

Workaround

See workaround in https://projects.theforeman.org/issues/29337#note-2