What about throwing if at least one place is defined?
The behavior would be:

• if you don't define any place => auto-guessed from transitions
• if you define at least one place => require them all to be listed (allowing some sort of strict mode definitions to be typo-safe)

The issues comes from the framework bundle. I want people to be able to

• not define dumb places
• define places with some metadata

framework:workflows:blog_publishing:metadata:title:'Blog Publishing Workflow'places:draft:metadata:max_num_of_words:500transitions:to_review:from:draftto:review

(fixed fabbot, phpunit failures seems not related)

Thank you@lyrixx.