mdbook-spec is an mdBook preprocessor that adds features to the Reference. It provides:
There are a few environment variables that mdbook-spec uses, described in Building the Reference:
SPEC_RELATIVE --- Can be set to link external books to the live site.SPEC_DENY_WARNINGS --- Whether warnings should be treated as errors.SPEC_RUST_ROOT --- The path to a checkout of the rust-lang/rust GitHub repository. This is used for test linking.