ICE: Broken MIR: generator contains type (on build) #83971

utherpally · 2021-04-07T15:07:29Z

Minimal example

Code

cargo run: ok.
cargo build: failed.

// https://github.com/http-rs/tide/blob/v0.16.0/src/middleware.rs
use async_trait::async_trait;
use std::future::Future;
use std::pin::Pin;

pub type Result = std::io::Result<()>;

#[async_trait]
pub trait Middleware<State>: Send   Sync   'static {
    /// Asynchronously handle the request, and return a response.
    async fn handle(&self, req: Request<State>, next: Next<'_, State>) -> crate::Result;

    /// Set the middleware's name. By default it uses the type signature.
    fn name(&self) -> &str {
        std::any::type_name::<Self>()
    }
}

pub struct Next<'a, State>(&'a str, State);

pub struct Request<State>(State);

#[async_trait]
impl<State, F> Middleware<State> for F
where
    State: Clone   Send   Sync   'static,
    F: Send
          Sync
          'static
          for<'a> Fn(
            Request<State>,
            Next<'a, State>,
        ) -> Pin<Box<dyn Future<Output = crate::Result>   'a   Send>>,
{
    async fn handle(&self, req: Request<State>, next: Next<'_, State>) -> crate::Result {
        (self)(req, next).await
    }
}

fn main() {

}

Error output

error: internal compiler error: compiler/rustc_mir/src/transform/generator.rs:751:13: Broken MIR: generator contains type Pin<Box<dyn Future<Output = std::result::Result<(), std::io::Error>>   Send>> in MIR, but typeck only knows about for<'r, 's, 't0> {ResumeTy, &'r F, Request<State>, Next<'s, State>, Pin<Box<(dyn Future<Output = std::result::Result<(), std::io::Error>>   Send   't0)>>, ()}

Backtrace

warning: function is never used: `main`
  --> src/lib.rs:39:4
   |
39 | fn main() {
   |    ^^^^
   |
   = note: `#[warn(dead_code)]` on by default

error: internal compiler error: compiler/rustc_mir/src/transform/generator.rs:751:13: Broken MIR: generator contains type Pin<Box<dyn Future<Output = std::result::Result<(), std::io::Error>>   Send>> in MIR, but typeck only knows about for<'r, 's, 't0> {ResumeTy, &'r F, Request<State>, Next<'s, State>, Pin<Box<(dyn Future<Output = std::result::Result<(), std::io::Error>>   Send   't0)>>, ()}
  --> src/lib.rs:34:89
   |
34 |       async fn handle(&self, req: Request<State>, next: Next<'_, State>) -> crate::Result {
   |  _________________________________________________________________________________________^
35 | |         (self)(req, next).await
36 | |     }
   | |_____^

thread 'rustc' panicked at 'Box<Any>', /rustc/c051c5ddda79f45fad196ca3a4690251e377d043/library/std/src/panic.rs:59:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug, I-ICE, T-compiler&template=ice.md

note: rustc 1.53.0-nightly (c051c5ddd 2021-04-06) running on x86_64-unknown-linux-gnu

note: compiler flags: -C opt-level=3 -C embed-bitcode=no -C codegen-units=1 --crate-type lib

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [optimized_mir] optimizing MIR for `<impl at src/lib.rs:23:1: 37:2>::handle::{closure#0}`
#1 [layout_raw] computing layout of `[static generator@src/lib.rs:34:89: 36:6 for<'r, 's, 't0> {std::future::ResumeTy, &'r F, Request<State>, Next<'s, State>, std::pin::Pin<std::boxed::Box<(dyn std::future::Future<Output = std::result::Result<(), std::io::Error>>   std::marker::Send   't0)>>, ()}]`
end of query stack
error: aborting due to previous error; 1 warning emitted

error: could not compile `playground`

To learn more, run the command again with --verbose.

The text was updated successfully, but these errors were encountered:

SNCPlay42 · 2021-04-07T15:56:59Z

Duplicate of #83737

utherpally added C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Apr 7, 2021

jonas-schievink closed this as completed Apr 9, 2021

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ICE: Broken MIR: generator contains type (on build) #83971

ICE: Broken MIR: generator contains type (on build) #83971

utherpally commented Apr 7, 2021

SNCPlay42 commented Apr 7, 2021

ICE: Broken MIR: generator contains type (on build) #83971

ICE: Broken MIR: generator contains type (on build) #83971

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utherpally commented Apr 7, 2021

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SNCPlay42 commented Apr 7, 2021