`struct` fields are now [private by default](https://github.com/mozilla/rust/pull/13184) (and have been for some time), so `priv` is no longer a keyword. There are a number of other cases in this RFC where you’ve assumed public fields by default (e.g. [line 232](https://github.com/rust-lang/rfcs/pull/78/files#diff-28aebdc1db45d6e4cb98ff9fce7a99fbR232)).