Function python_symbols 

fn python_symbols() -> Result<BTreeMap<String, String>, Error>

Every Python symbol, as its dotted path → page.md#anchor.

The top-level module’s members carry a mkdocstrings anchor each — one per class, function and member, minted from the live object’s canonical path — and mkdocs build --strict validates every one of them. The two #[pymodule] submodules have no ::: block to mint anchors from (§1.3.49), so their symbols point at the section that documents them.

A submodule is reached twice: once as a member of the top-level surface and once as a surface of its own, and it is the first of those that produced this generator’s one fail-open bug (§1.3.106) — atune.samplers was written with a mkdocstrings anchor because the enclosing surface has no section, even though the symbol itself is a submodule. The section is therefore looked up by the symbol’s own dotted path first, and check_submodules_use_their_section re-checks the whole map afterwards so the same slip cannot come back through a different route.

An alias is the second such trap and produced the same class of dead link. atune.TrialPruned and atune.Pruned are one live class object bound under two names, so mkdocstrings renders it once and mints one anchor, from the canonical path; a per-name anchor for the second spelling never exists. The map therefore points an alias at its target’s anchor — the section of the page that does document the object — and resolve_aliases fails closed if the target resolved to nothing, because a silently dropped alias is the dead link this pass exists to remove.