Remove dependency on prettyplease The functionality provided by prettyplease is purely cosmetic and is not used by any package in Debian. Remove it to avoid packaging an additional dependency which is not needed at the moment. Also drop the 'format' feature, which depends on it.
drop feature cleanup-markdown The cleanup-markdown feature depends on pulldown-cmark-to-cmark, which is not packaged in Debian. Drop the feature to make the dependencies of librust-prost-build-dev satisfiable.
