panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1425:13

[amarao]

Code

#[derive(Debug, Clone, Copy)]
struct Foo<T>{
    value: T
}

impl<T: Copy + std::ops::AddAssign, R: Into<Foo<T>>> std::ops::AddAssign<R>
    for Foo<T>
{
    fn add_assign(&mut self, rhs: R)
    {
        let rhs = rhs.into();
        self.value+=rhs.value
    }
}

impl<T: Copy + std::ops::AddAssign, R: Into<Foo<T>>> std::ops::AddAssign<R>
    for &mut Foo<T>
{
    fn add_assign(&mut self, rhs: R)
    {
        let rhs = rhs.into();
        self.value+=rhs.value
    }
}

impl<T> From<&Self> for Foo<T>
where
    T: Copy
{
    #[inline]
    #[must_use]
    fn from(value: &Self) -> Self
    {
        Foo{value: value.value}
    }
}

fn main(){
    let mut left = Foo{value:1};
    let right = Foo{value:1};
    left += right;
    (&mut left) += &right;

}

Meta

rustc --version --verbose:

rustc 1.63.0 (4b91a6ea7 2022-08-08)
binary: rustc
commit-hash: 4b91a6ea7258a947e59c6522cd5898e7c0a6a88f
commit-date: 2022-08-08
host: x86_64-unknown-linux-gnu
release: 1.63.0
LLVM version: 14.0.5

Error output

RUST_BACKTRACE=full cargo run
   Compiling test_ref_ops v0.1.0 (/tmp/test_ref_ops)
warning: Error finalizing incremental compilation session directory `/tmp/test_ref_ops/target/debug/incremental/test_ref_ops-3s18srsj0fhdf/s-gd7b1v07dk-1anujo-working`: No such file or directory (os error 2)

error: internal compiler error: no errors encountered even though `delay_span_bug` issued

error: internal compiler error[E0067]: invalid left-hand side of assignment
  --> src/main.rs:42:17
   |
42 |     (&mut left) += &right;
   |     ----------- ^^
   |     |
   |     cannot assign to this expression

thread 'rustc' panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1425:13
stack backtrace:
   0:     0x7f038a89e18d - std::backtrace_rs::backtrace::libunwind::trace::h8217d0a8f3fd2f41
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f038a89e18d - std::backtrace_rs::backtrace::trace_unsynchronized::h308103876b3af410
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f038a89e18d - std::sys_common::backtrace::_print_fmt::hc208018c6153605e
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7f038a89e18d - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hf89a7ed694dfb585
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7f038a8f9f7c - core::fmt::write::h21038c1382fe4264
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/core/src/fmt/mod.rs:1197:17
   5:     0x7f038a88f8a1 - std::io::Write::write_fmt::h7dbb1c9a3c254aef
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/io/mod.rs:1672:15
   6:     0x7f038a8a0e55 - std::sys_common::backtrace::_print::h4e8889719c9ddeb8
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7f038a8a0e55 - std::sys_common::backtrace::print::h1506fe2cb3022667
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7f038a8a0e55 - std::panicking::default_hook::{{closure}}::hd9d7ce2a8a782440
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:295:22
   9:     0x7f038a8a0b76 - std::panicking::default_hook::h5b16ec25444b1b5d
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:314:9
  10:     0x7f038b0feb54 - rustc_driver[e01eec72899701d3]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7f038a8a152a - std::panicking::rust_panic_with_hook::hb0138cb6e6fea3e4
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/panicking.rs:702:17
  12:     0x7f038c2baa91 - std[f9ee9c7d4fd68eda]::panicking::begin_panic::<rustc_errors[b2e8492a1747ee42]::ExplicitBug>::{closure#0}
  13:     0x7f038c2b8036 - std[f9ee9c7d4fd68eda]::sys_common::backtrace::__rust_end_short_backtrace::<std[f9ee9c7d4fd68eda]::panicking::begin_panic<rustc_errors[b2e8492a1747ee42]::ExplicitBug>::{closure#0}, !>
  14:     0x7f038c2c7806 - std[f9ee9c7d4fd68eda]::panicking::begin_panic::<rustc_errors[b2e8492a1747ee42]::ExplicitBug>
  15:     0x7f038c2c4ad6 - std[f9ee9c7d4fd68eda]::panic::panic_any::<rustc_errors[b2e8492a1747ee42]::ExplicitBug>
  16:     0x7f038db7ecec - <rustc_errors[b2e8492a1747ee42]::HandlerInner as core[3edb0f9afb6adb32]::ops::drop::Drop>::drop
  17:     0x7f038d2a9348 - core[3edb0f9afb6adb32]::ptr::drop_in_place::<rustc_session[72c90254a58d88d1]::parse::ParseSess>
  18:     0x7f038d2ac2e3 - <alloc[59e4fb8ddcfb913c]::rc::Rc<rustc_session[72c90254a58d88d1]::session::Session> as core[3edb0f9afb6adb32]::ops::drop::Drop>::drop
  19:     0x7f038d2ab6bd - core[3edb0f9afb6adb32]::ptr::drop_in_place::<rustc_interface[be6c6c80f2cd8cf2]::interface::Compiler>
  20:     0x7f038d2a8c54 - rustc_span[fb9cf5df1e5e5539]::with_source_map::<core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>, rustc_interface[be6c6c80f2cd8cf2]::interface::create_compiler_and_run<core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>, rustc_driver[e01eec72899701d3]::run_compiler::{closure#1}>::{closure#1}>
  21:     0x7f038d2b0302 - <scoped_tls[134a193f706323ee]::ScopedKey<rustc_span[fb9cf5df1e5e5539]::SessionGlobals>>::set::<rustc_interface[be6c6c80f2cd8cf2]::interface::run_compiler<core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>, rustc_driver[e01eec72899701d3]::run_compiler::{closure#1}>::{closure#0}, core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>>
  22:     0x7f038d2d399f - std[f9ee9c7d4fd68eda]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[be6c6c80f2cd8cf2]::util::run_in_thread_pool_with_globals<rustc_interface[be6c6c80f2cd8cf2]::interface::run_compiler<core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>, rustc_driver[e01eec72899701d3]::run_compiler::{closure#1}>::{closure#0}, core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>>::{closure#0}, core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>>
  23:     0x7f038d2c5529 - <<std[f9ee9c7d4fd68eda]::thread::Builder>::spawn_unchecked_<rustc_interface[be6c6c80f2cd8cf2]::util::run_in_thread_pool_with_globals<rustc_interface[be6c6c80f2cd8cf2]::interface::run_compiler<core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>, rustc_driver[e01eec72899701d3]::run_compiler::{closure#1}>::{closure#0}, core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>>::{closure#0}, core[3edb0f9afb6adb32]::result::Result<(), rustc_errors[b2e8492a1747ee42]::ErrorGuaranteed>>::{closure#1} as core[3edb0f9afb6adb32]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  24:     0x7f038a8ab463 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h1680342795a2dc08
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/alloc/src/boxed.rs:1951:9
  25:     0x7f038a8ab463 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h45204a69827b0e83
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/alloc/src/boxed.rs:1951:9
  26:     0x7f038a8ab463 - std::sys::unix::thread::Thread::new::thread_start::h5d4e11bbda4161c8
                               at /rustc/4b91a6ea7258a947e59c6522cd5898e7c0a6a88f/library/std/src/sys/unix/thread.rs:108:17
  27:     0x7f038a686b27 - start_thread
                               at ./nptl/./nptl/pthread_create.c:435:8
  28:     0x7f038a70978c - __GI___clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  29:                0x0 - <unknown>

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%2C+I-ICE%2C+T-compiler&template=ice.md

note: rustc 1.63.0 (4b91a6ea7 2022-08-08) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C incremental

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

query stack during panic:
end of query stack
warning: `test_ref_ops` (bin "test_ref_ops") generated 1 warning
error: could not compile `test_ref_ops`; 1 warning emitted

[amarao]

(update, I've reproduced it on smaller example)

[steffahn]

Error -> ICE
regression in 1.63 @rustbot label regression-from-stable-to-stable

[QuineDot]

Reduced example (stable, nightly, beta).

use std::ops::AddAssign;
struct Foo;

impl AddAssign<()> for Foo {
    fn add_assign(&mut self, _: ()) {}
}

impl AddAssign<()> for &mut Foo {
    fn add_assign(&mut self, _: ()) {}
}

fn main() {
    (&mut Foo) += ();
}

There's no ICE on 1.62.

[steffahn]

searched nightlies: from nightly-2022-05-01 to nightly-2022-07-01
regressed nightly: nightly-2022-05-19
searched commit range: 4c5f6e6...cd282d7
regressed commit: a084b7a

bisected with cargo-bisect-rustc v0.6.4

Host triple: x86_64-unknown-linux-gnu
Reproduce with:

cargo-bisect-rustc --access github --regress ice --start 2022-05-01 --end 2022-07-01 -vv

---

Regresses in rollup #97135, most likely #94639, cc @compiler-errors

[compiler-errors]

@rustbot claim