WriteOnly simply derives Clone so it calls `Volatile::clone` to clone its field, https://github.com/embed-rs/volatile/blob/a5a6d786995df7cf07ed8689f79805da10ba2429/src/lib.rs#L210-L211 but `Volatile::clone` uses `Volatile::read` internally which might not work since the value is write-only. https://github.com/embed-rs/volatile/blob/a5a6d786995df7cf07ed8689f79805da10ba2429/src/lib.rs#L144-L148 Removing Clone from WriteOnly is obviously a breaking change, so I'm not sure what to do about this.