Cannot derive remote serialize for #[non_exhaustive] enum

[abonander]

Attempting to use a remote derive for gstreamer_webrtc::WebRTCSDPType:

#[derive(Serialize, Deserialize)]
#[serde(rename_all = "snake_case", remote = "WebRTCSDPType")]
#[non_exhaustive]
pub enum SdpType {
    /// offer
    Offer,
    /// pranswer
    Pranswer,
    /// answer
    Answer,
    /// rollback
    Rollback,
}

produces the following error:

error[E0004]: non-exhaustive patterns: `_` not covered
  --> src/foo.rs:96:10
   |
96 | #[derive(Serialize, Deserialize)]
   |          ^^^^^^^^^ pattern `_` not covered
   |
   = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
   = note: the matched value is of type `WebRTCSDPType`
   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

This can't be reproduced in a single-crate example, however, because #[non_exhaustive] isn't enforced for crate-local enums: https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=084b2a4a7888fc0069d5b368e0bc6d0f

[soywod]

I got the same issue, how to deal with it?

[anden3]

I have the same issue, so I resorted to patching the remote crate for now.

[rhysd]

Compile error is different, but I see a similar issue on serde v1.0.184.

I created a small reproduction.

#[non_exhaustive]
#[derive(Serialize)]
enum E {
  S(String),
}

Compiling this code with rustc v1.71.1 caused the following error:

error[E0507]: cannot move out of `*self` which is behind a shared reference
    --> src\keyboard.rs:1601:17
     |
1601 | #[derive(Debug, Serialize)]
     |                 ^^^^^^^^^
     |                 |
     |                 data moved here
     |                 move occurs because `unrecognized` has type `E`, which does not implement the `Copy` trait
     |
     = note: this error originates in the derive macro `Serialize` (in Nightly builds, run with -Z macro-backtrace for more info)
help: consider borrowing here
     |
1601 | #[derive(Debug, &Serialize)]
     |                 +

For more information about this error, try `rustc --explain E0507`.

[dtolnay]

Fixed in serde_derive 1.0.185.

I wasn't able to build gstreamer-webrtc on my machine, but I tested with std::io::ErrorKind which should be effectively equivalent; please let me know if there is still any issue with the original use case.

use serde::{Deserialize, Serialize};

#[derive(Deserialize, Serialize)]
#[serde(remote = "std::io::ErrorKind")]
#[non_exhaustive]
pub enum ErrorKind {
    NotFound,
    PermissionDenied,
}

[rhysd]

I confirmed the fix. Thanks for the quick release.

[Dominilk]

This needs to be documented more clearly. It's not mentioned in https://serde.rs/remote-derive.html. Error message is misleading.