check-doc-refs.sh's relative arm resolved every link against the linking
file's directory. That is right for markdown and wrong for a .rs doc
comment: rustdoc emits the href verbatim onto a page under
target/doc/<crate>/<module...>/, so the link resolves against THAT
directory instead.
The consequence was a false pass, not a miss -- a link resolving from the
source dir got certified while rendering broken in the published docs.
Reproduced against main's script: a `](../../docs/README.md)` planted in
hive-forge/src/client.rs resolves from hive-forge/src/ and the old rule
exits 0.
Refused rather than resolved rustdoc-aware. The repo has zero relative
links in .rs doc comments (measured on 54daf9ac), so nothing needs the
second reader, and the backticked repo-root form the root arm already
gates renders correctly under both. Inferring module nesting would be
machinery in service of a form nothing uses.
Closes#3928
Pointing at a doc instead of duplicating its prose next to the code is what
the comment-block lint pushes people toward, and nothing checked that the
pointers still resolve. The reorg that prompted the preceding commit broke
41 references and every one of them merged green.
Two arms: repo-root-relative `docs/` paths, and relative markdown links
resolved against the linking file. Scope is every tracked file rather than a
type list — the dead references were in css, html and an ignore file as well
as in markdown and nix.
Three controls, because a link checker whose extractor quietly matches
nothing passes forever while checking nothing: each arm must have found
candidates, and at least one pointer must have resolved. Any of those failing
exits non-zero and says the script is broken rather than the tree.
Escape hatch is the `lint:allow` marker the tracker-tag lint already uses.
Its only current users are in reference-docs.nix, where a path naming a file
the derivation synthesizes into $out is correct precisely because the repo
does not have it.
Also runs in the pre-push hook alongside the other two.
