How to customize a merge request message on Gitlab?
Globally, automatically - I don't think so. As I see, it's hard-coded:
message = [ "Merge branch '#{source_branch}' into '#{target_branch}'", title ] if !include_description && closes_issues_references.present? message << "Closes #{closes_issues_references.to_sentence}" end message << "#{description}" if include_description && description.present? message << "See merge request #{to_reference}" message.join("\n\n")
You can override message for any merge request manually:
It's also possible if you create merge request with API. It requires your time but you can build some mechanism that fetches all data with API and set it as a description (but you must ensure all is available with API, issueDescription and so on).