I already quoted the relevant section in my last post:
The mail does not claim the document is meant to be PEP8. It merely specifies API conventions to have a uniform API across libraries for 1.0.
Even if it was supposed to be PEP8 for rust, I'd be against that, too. It is absolutely ridiculous that a language enforce (if rustfmt is commonly used to enforce spacing conventions, that is) both braces AND whitespace. Rust has already decided to be a braces-and-semicolons language. Don't enforce whitespace rules or brace placement rules.