Function compose 

pub fn compose(root: &Path, objects: &[Object]) -> Changelog

Compose the changelog, unreleased section included.

objects is the index’s own view of the layer; root is the repository git reads. A repository with no records yields one unreleased section, which is the right answer for a project that has never published rather than an error.

This is what a live reader wants — the API, MCP and the Cockpit answer at request time and HEAD is whatever it is then. It is not what a committed artifact may hold: see compose_published.