Noted and noted.
I have not used this list for anything yet, but I really should have. After the big rustbuild change I am positive that broke downstream packaging.
Other changes recently have included the way we vendor sources. At the moment, only the tarballs come with vendored dependencies, and are thus able to build offline (theoretically). The git sources do not contain the vendored dependencies.
The other big change I would have told packagers is that we are now bundling all the Rust tooling that we consider part of the the Rust product in tree, and I’d suggest packagers source e.g. cargo from there, and no longer attempt to obtain it independently. The same will soon be true of rls, rustfmt and clippy. All these things will at some point in the near future be part of Rust proper.