ICE with "failed to resolve instance for <... as IntoFuture>::into_future: Ok(None)" (regression between 1.73 and 1.74) #119095
Labels
A-async-await
Area: Async & Await
A-auto-traits
Area: auto traits (e.g., `auto trait Send {}`)
AsyncAwait-Triaged
Async-await issues that have been triaged during a working group meeting.
C-bug
Category: This is a bug.
I-ICE
Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️
P-medium
Medium priority
regression-from-stable-to-stable
Performance or correctness regression from one stable version to another.
S-bug-has-test
Status: This bug is tracked inside the repo by a `known-bug` test.
S-has-mcve
Status: A Minimal Complete and Verifiable Example has been found for this issue
T-compiler
Relevant to the compiler team, which will review and decide on the PR/issue.
WG-async
Working group: Async & await
Comments
42triangles
added
C-bug
rustbot
added
the
needs-triage
fmease
added
the
E-needs-mcve
compiler-errors
added
the
E-needs-bisection
|
I remembered that when I first saw this (and didn't have enough time to minimize it to the degree I have here), it had a different error message. use std::{net::SocketAddr, future::Future, sync::Arc};
use warp::{reply::Reply, Filter};
use sqlx::postgres::Postgres;
fn login<'a>(
db: impl sqlx::Acquire<'a, Database = sqlx::Postgres> + Send + 'a,
) -> impl Future<Output = ()> + Send + 'a {
async move {
sqlx::query_scalar::<Postgres, i64>("")
.fetch_one(&mut *db.acquire().await.unwrap())
.await
.unwrap();
}
}
#[tokio::main(flavor = "current_thread")]
async fn main() {
let db = Arc::new(sqlx::postgres::PgPool::connect("").await.unwrap());
let app = warp::path!()
.then(move || {
let db = db.clone();
async move {
login(&mut *db.begin().await.unwrap()).await;
"".into_response()
}
})
.recover(move |_| async {
Ok::<String, warp::Rejection>(panic!("not yet implemented"))
})
.boxed();
warp::serve(app).run(SocketAddr::new([0, 0, 0, 0].into(), 8080)).await;
}Results in an ICE, which is likely related, with this error message ("unexpected unsized tail"): Backtrace (with `RUST_BACKTRACE=full`, same stable version)
|
|
@rustbot label regression-from-stable-to-stable A-async-await |
rustbot
added
A-async-await
rustbot
removed
the
E-needs-bisection
|
It's easy to remove This is the The codeuse std::future::{self, Future};
use std::marker::PhantomData;
use std::pin::Pin;
use std::sync::Arc;
use std::task::Context;
use std::task::Poll;
trait Acquire<'c> {
type Connection;
fn acquire(self) -> Pin<Box<dyn Future<Output = Result<Self::Connection, ()>> + Send + 'c>>;
}
struct PgConnection;
impl<'c> Acquire<'c> for &'c mut PgConnection {
type Connection = ();
fn acquire(self) -> Pin<Box<dyn Future<Output = Result<Self::Connection, ()>> + Send + 'c>> {
unimplemented!()
}
}
fn login<'a>(db: impl Acquire<'a> + Send + 'a) -> impl Future<Output = ()> + Send + 'a {
async move {
let _ = db.acquire().await;
}
}
fn main() {
path()
.then(|| async {
let mut conn = PgConnection;
login(&mut conn).await;
})
.then(|_| async { unimplemented!() })
.boxed();
}
fn path() -> impl Filter<Extract = (), Error = ()> {
filter_fn(move || future::ready(Err(())))
}
struct Then<T, F> {
_marker: PhantomData<(T, F)>,
}
impl<T, F> FilterBase for Then<T, F>
where
T: Filter,
F: Func<T::Extract> + Clone + Send,
F::Output: Future + Send,
{
type Extract = (<F::Output as Future>::Output,);
type Error = T::Error;
type Future = ThenFuture<T, F>;
}
struct ThenFuture<T, F>
where
T: Filter,
F: Func<T::Extract>,
F::Output: Future + Send,
{
_state: State<T::Future, F>,
}
enum State<T, F>
where
T: TryFuture,
F: Func<T::Ok>,
F::Output: Future + Send,
{
Second(F::Output),
}
impl<T, F> Future for ThenFuture<T, F>
where
T: Filter,
F: Func<T::Extract>,
F::Output: Future + Send,
{
type Output = Result<(<F::Output as Future>::Output,), T::Error>;
fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Self::Output> {
unimplemented!()
}
}
struct MapErr<T, F> {
_filter: T,
_callback: F,
}
impl<T, F, E> FilterBase for MapErr<T, F>
where
T: Filter,
F: Fn(T::Error) -> E + Clone + Send,
{
type Extract = T::Extract;
type Error = E;
type Future = MapErrFuture<T, F>;
}
struct MapErrFuture<T: Filter, F> {
_extract: T::Future,
_callback: F,
}
impl<T, F, E> Future for MapErrFuture<T, F>
where
T: Filter,
F: Fn(T::Error) -> E,
{
type Output = Result<T::Extract, E>;
fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Self::Output> {
unimplemented!()
}
}
struct BoxedFilter<T> {
_filter: Arc<
dyn Filter<
Extract = T,
Error = (),
Future = Pin<Box<dyn Future<Output = Result<T, ()>> + Send>>,
> + Send
+ Sync,
>,
}
impl<T: Send> BoxedFilter<T> {
fn new<F>(filter: F) -> BoxedFilter<T>
where
F: Filter<Extract = T> + Send + Sync + 'static,
F::Error: Into<()>,
{
let filter = Arc::new(BoxingFilter {
filter: filter.map_err(Internal, Into::into),
});
BoxedFilter { _filter: filter }
}
}
struct BoxingFilter<F> {
filter: F,
}
impl<F> FilterBase for BoxingFilter<F>
where
F: Filter,
F::Future: Send + 'static,
{
type Extract = F::Extract;
type Error = F::Error;
type Future = Pin<Box<dyn Future<Output = Result<Self::Extract, Self::Error>> + Send>>;
fn filter(&self, _: Internal) -> Self::Future {
Box::pin(self.filter.filter(Internal).into_future())
}
}
trait FilterBase {
type Extract;
type Error;
type Future: Future<Output = Result<Self::Extract, Self::Error>> + Send;
fn filter(&self, _internal: Internal) -> Self::Future {
unimplemented!()
}
fn map_err<F, E>(self, _internal: Internal, _fun: F) -> MapErr<Self, F>
where
Self: Sized,
F: Fn(Self::Error) -> E + Clone,
E: Send,
{
unimplemented!()
}
}
struct Internal;
trait Filter: FilterBase {
fn then<F>(self, _fun: F) -> Then<Self, F>
where
Self: Sized,
F: Func<Self::Extract> + Clone,
F::Output: Future + Send,
{
unimplemented!()
}
fn boxed(self) -> BoxedFilter<Self::Extract>
where
Self: Sized + Send + Sync + 'static,
Self::Extract: Send,
Self::Error: Into<()>,
{
BoxedFilter::new(self)
}
}
impl<T: FilterBase> Filter for T {}
fn filter_fn<F, U>(_func: F) -> FilterFn<F>
where
F: Fn() -> U,
U: TryFuture,
{
unimplemented!()
}
struct FilterFn<F> {
_func: F,
}
impl<F, U> FilterBase for FilterFn<F>
where
F: Fn() -> U,
U: TryFuture + Send + 'static,
{
type Extract = U::Ok;
type Error = U::Error;
type Future = IntoFuture<U>;
}
trait Func<Args> {
type Output;
}
impl<F, R> Func<()> for F
where
F: Fn() -> R,
{
type Output = R;
}
impl<F, R, T2> Func<(T2,)> for F
where
F: Fn(T2) -> R,
{
type Output = R;
}
trait TryFuture: Future {
type Ok;
type Error;
fn into_future(self) -> IntoFuture<Self>
where
Self: Sized,
{
unimplemented!()
}
}
impl<F, T, E> TryFuture for F
where
F: ?Sized + Future<Output = Result<T, E>>,
{
type Ok = T;
type Error = E;
}
struct IntoFuture<Fut> {
_future: Fut,
}
impl<Fut: TryFuture> Future for IntoFuture<Fut> {
type Output = Result<Fut::Ok, Fut::Error>;
fn poll(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Self::Output> {
unimplemented!()
}
} |
saethlin
removed
the
needs-triage
|
@rustbot labels +AsyncAwait-Triaged +WG-async We reviewed this today in WG-async triage. It sounds like a bug. |
rustbot
added
AsyncAwait-Triaged
|
The reproduction by lqd above no longer ICEs now, but the original example still does, so here is a new reduced version that ICEs with use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
fn any<T>() -> T {
todo!()
}
#[allow(clippy::manual_async_fn)]
fn login<'a>(db: impl Acquire<'a> + Send + 'a) -> impl Future + Send + 'a {
async {
db.acquire().await;
}
}
type BoxFuture<T> = Pin<Box<dyn Future<Output = T> + Send>>;
trait Acquire<'c> {
type Connection;
fn acquire(self) -> BoxFuture<Self::Connection>;
}
impl<'c> Acquire<'c> for &'c () {
type Connection = ();
fn acquire(self) -> BoxFuture<Self::Connection> {
todo!()
}
}
struct Then<F>(F);
impl<F> Future for Then<F>
where
F: Send,
{
type Output = ();
fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<()> {
todo!()
}
}
fn main() {
let app = Then(async {
login(any::<&'static ()>()).await;
});
#[allow(clippy::async_yields_async)]
let mut future = Box::pin(Server(async { app }));
let _ = future.as_mut().poll(any::<&mut Context>());
}
trait ConnStreamExec<F> {}
impl<F> ConnStreamExec<F> for () where F: Future {}
struct Server<S>(S);
impl<S> Future for Server<S>
where
S: Future,
(): ConnStreamExec<S::Output>,
{
type Output = ();
fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<()> {
todo!()
}
}
trait NeverImplemented {}
impl<E, F> ConnStreamExec<F> for E where E: NeverImplemented {}Error
|
|
Minimized further: use std::future::Future;
fn any<T>() -> T {
todo!()
}
trait Acquire {
type Connection;
}
impl Acquire for &'static () {
type Connection = ();
}
fn get_connection<T: Acquire>() -> impl Future + Send {
async { any::<T::Connection>() }
}
fn main() {
let future = async {
get_connection::<&'static ()>().await;
};
future.resolve_me();
}
pub trait ResolveMe {
fn resolve_me(self);
}
impl<S> ResolveMe for S
where
(): CheckSend<S>,
{
fn resolve_me(self) {}
}
trait CheckSend<F> {}
impl<F> CheckSend<F> for () where F: Send {}
trait NeverImplemented {}
impl<E, F> CheckSend<F> for E where E: NeverImplemented {} |
|
Another example, which doesn't mention any #![feature(auto_traits)]
auto trait Auto {}
fn any<T>() -> T {
loop {}
}
trait Acquire {
type Connection;
}
impl Acquire for &'static () {
type Connection = ();
}
trait Unit {}
impl Unit for () {}
fn get_connection<T>() -> impl Unit
where
T: Acquire,
T::Connection: Unit,
{
any::<T::Connection>()
}
fn main() {
let future = async { async { get_connection::<&'static ()>() }.await };
future.resolve_me();
}
trait ResolveMe {
fn resolve_me(self);
}
impl<S> ResolveMe for S
where
(): CheckAuto<S>,
{
fn resolve_me(self) {}
}
trait CheckAuto<F> {}
impl<F> CheckAuto<F> for () where F: Auto {}
trait NeverImplemented {}
impl<E, F> CheckAuto<F> for E where E: NeverImplemented {}I wasn't able to reproduce it with the following replacement although I thought it would have the same effect: // works
trait Auto {}
impl<T: ?Sized> Auto for T {} |
workingjubilee
added a commit
to workingjubilee/rustc
that referenced
this issue
Aug 31, 2024
add crashtests for several old unfixed ICEs Adds several new crashtests for some older ICEs that did not yet have any. Tests were added for rust-lang#128097, rust-lang#119095, rust-lang#117460 and rust-lang#126443.
matthiaskrgr
added a commit
to matthiaskrgr/rust
that referenced
this issue
Sep 1, 2024
add crashtests for several old unfixed ICEs Adds several new crashtests for some older ICEs that did not yet have any. Tests were added for rust-lang#128097, rust-lang#119095, rust-lang#117460 and rust-lang#126443.
rust-timer
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that referenced
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Sep 1, 2024
Rollup merge of rust-lang#129780 - cyrgani:master, r=compiler-errors add crashtests for several old unfixed ICEs Adds several new crashtests for some older ICEs that did not yet have any. Tests were added for rust-lang#128097, rust-lang#119095, rust-lang#117460 and rust-lang#126443.
matthiaskrgr
added
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S-bug-has-test
|
@rustbot label: -E-needs-mcve +A-auto-traits +S-has-mcve |
rustbot
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|
WG-prioritization assigning priority (Zulip discussion). @rustbot label -I-prioritize +P-medium |
rustbot
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Code
with the dependencies
Meta
rustc --version --verbose:It doesn't work on nightly, beta or stable (from 17.74 onward):
Beta, stable, 1.74
Notably, the code does compiles with 1.73:
Error output
1.74 & stable:
beta and nightly:
Backtrace (`RUST_BACKTRACE=1`)
Backtrace (`RUST_BACKTRACE=full`)
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