  * fail early if a rust-*-dev package does not match contained crates
    * each contained crate must match a provided virtual fullname package
    * each virtual fullname package names must match a contained crate
  * resolve ${rust:Provides}
    <https://bugs.debian.org/1076437>
  * support appending subproject version to binary package version
    <https://bugs.debian.org/1076434>
    * affects oxigraph
  * handle CARGO_HOME internally (not in Python-based wrapper "cargo")
    <https://bugs.debian.org/1076440>
    * support custom location of cargo_home
      * affects helvum
    * support building intermediaries through calling `cargo run`
      * affects rust-tonic
