[ICE]: maybe try to call `try_normalize_erasing_regions` instead

[wxie7]

Code

use std::hint::black_box;
trait Func {
    type Ret: Id;
}
trait Id {
    type Assoc;
}
fn main() {}
impl Id for i32 {
    type Assoc = i32;
}
impl<F: FnOnce() -> R, R: Id> Func for F {
    type Ret = R;
}
fn bar() -> impl Copy + Id {
    0u32
}
struct Foo<T: Func> {
    _func: T,
    value: Option<<<T as Func>::Ret as Id>::Assoc>,
}
fn main() {
    let mut fn_def = black_box(Foo {
        _func: bar,
        value: None,
    });
    let fn_ptr = black_box(Foo {
        _func: bar as fn() -> _,
        value: None,
    });
    fn_def.value = fn_ptr.value;
    black_box(fn_def);
}

Meta

rustc --version --verbose:

rustc 1.84.0-nightly (b91a3a056 2024-11-07)
binary: rustc
commit-hash: b91a3a05609a46f73d23e0995ae7ebb4a4f429a5
commit-date: 2024-11-07
host: x86_64-unknown-linux-gnu
release: 1.84.0-nightly
LLVM version: 19.1.3

Error output

error[E0428]: the name `main` is defined multiple times
  --> mutant.rs:22:1
   |
8  | fn main() {}
   | --------- previous definition of the value `main` here
...
22 | fn main() {
   | ^^^^^^^^^ `main` redefined here
   |
   = note: `main` must be defined only once in the value namespace of this module

error[E0277]: the trait bound `u32: Id` is not satisfied
  --> mutant.rs:15:13
   |
15 | fn bar() -> impl Copy + Id {
   |             ^^^^^^^^^^^^^^ the trait `Id` is not implemented for `u32`
16 |     0u32
   |     ---- return type was inferred to be `u32` here
   |
   = help: the trait `Id` is implemented for `i32`

error: internal compiler error: compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:169:90: Failed to normalize std::option::Option<Alias(Projection, AliasTy { args: [Alias(Projection, AliasTy { args: [FnDef(DefId(0:15 ~ mutant[20f1]::bar), [])], def_id: DefId(0:5 ~ mutant[20f1]::Func::Ret), .. })], def_id: DefId(0:7 ~ mutant[20f1]::Id::Assoc), .. })>, maybe try to call `try_normalize_erasing_regions` instead

thread 'rustc' panicked at compiler/rustc_middle/src/ty/normalize_erasing_regions.rs:169:90:
Box<dyn Any>
stack backtrace:
...
note: compiler flags: --crate-type staticlib -C link-dead-code -C debuginfo=2 -C opt-level=3 -Z mir-opt-level=3

query stack during panic:
#0 [mir_drops_elaborated_and_const_checked] elaborating drops for `main`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 3 previous errors

Some errors have detailed explanations: E0277, E0428.
For more information about an error, try `rustc --explain E0277`.

Backtrace

stack backtrace:
   0:     0x7fde3585517a - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hfadad24fb33e3d1a
   1:     0x7fde360040a6 - core::fmt::write::h42d25fbda60cd99f
   2:     0x7fde373c3351 - std::io::Write::write_fmt::hc2819193e80b365e
   3:     0x7fde35854fd2 - std::sys::backtrace::BacktraceLock::print::h9450230402d77664
   4:     0x7fde358574d6 - std::panicking::default_hook::{{closure}}::h739047d4d787c596
   5:     0x7fde35857320 - std::panicking::default_hook::h203d1229480f37a5
   6:     0x7fde348d2269 - std[56fe22ad9ea837fd]::panicking::update_hook::<alloc[b5641001d343df5f]::boxed::Box<rustc_driver_impl[945e9afaf49c7d35]::install_ice_hook::{closure#0}>>::{closure#0}
   7:     0x7fde35857be8 - std::panicking::rust_panic_with_hook::h657fdcc17f7e2546
   8:     0x7fde3490c191 - std[56fe22ad9ea837fd]::panicking::begin_panic::<rustc_errors[43c84716ac990581]::ExplicitBug>::{closure#0}
   9:     0x7fde348ff166 - std[56fe22ad9ea837fd]::sys::backtrace::__rust_end_short_backtrace::<std[56fe22ad9ea837fd]::panicking::begin_panic<rustc_errors[43c84716ac990581]::ExplicitBug>::{closure#0}, !>
  10:     0x7fde348feefe - std[56fe22ad9ea837fd]::panicking::begin_panic::<rustc_errors[43c84716ac990581]::ExplicitBug>
  11:     0x7fde34915e71 - <rustc_errors[43c84716ac990581]::diagnostic::BugAbort as rustc_errors[43c84716ac990581]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  12:     0x7fde34f8f2c3 - rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt::<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}
  13:     0x7fde34f758ba - rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_opt::<rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  14:     0x7fde34f7574b - rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_context_opt::<rustc_middle[f0eb6ba890d0a9bb]::ty::context::tls::with_opt<rustc_middle[f0eb6ba890d0a9bb]::util::bug::opt_span_bug_fmt<rustc_span[db86d96c2ae2e3a4]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  15:     0x7fde331e7300 - rustc_middle[f0eb6ba890d0a9bb]::util::bug::bug_fmt
  16:     0x7fde368f39bc - <rustc_middle[f0eb6ba890d0a9bb]::ty::normalize_erasing_regions::NormalizeAfterErasingRegionsFolder as rustc_type_ir[8408d34320f8a6fb]::fold::TypeFolder<rustc_middle[f0eb6ba890d0a9bb]::ty::context::TyCtxt>>::fold_ty
  17:     0x7fde3643e8af - <rustc_mir_dataflow[d330eec8ae5b9552]::elaborate_drops::DropCtxt<rustc_mir_transform[c62e463fc59f8bd1]::elaborate_drops::ElaborateDropsCtxt>>::elaborate_drop
  18:     0x7fde32a290dd - <rustc_mir_transform[c62e463fc59f8bd1]::elaborate_drops::ElaborateDrops as rustc_mir_transform[c62e463fc59f8bd1]::pass_manager::MirPass>::run_pass
  19:     0x7fde36009348 - rustc_mir_transform[c62e463fc59f8bd1]::run_analysis_to_runtime_passes
  20:     0x7fde362ddb58 - rustc_mir_transform[c62e463fc59f8bd1]::mir_drops_elaborated_and_const_checked
  21:     0x7fde362dd45b - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_drops_elaborated_and_const_checked::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>
  22:     0x7fde36723681 - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::VecCache<rustc_span[db86d96c2ae2e3a4]::def_id::LocalDefId, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  23:     0x7fde367230cd - rustc_query_impl[1357963d8dd30e8b]::query_impl::mir_drops_elaborated_and_const_checked::get_query_non_incr::__rust_end_short_backtrace
  24:     0x7fde36869488 - rustc_interface[5fea8bf9cd0b71b5]::passes::run_required_analyses
  25:     0x7fde36e0861e - rustc_interface[5fea8bf9cd0b71b5]::passes::analysis
  26:     0x7fde36e085ef - rustc_query_impl[1357963d8dd30e8b]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>
  27:     0x7fde36f92cee - rustc_query_system[887bb79932b1d8c1]::query::plumbing::try_execute_query::<rustc_query_impl[1357963d8dd30e8b]::DynamicConfig<rustc_query_system[887bb79932b1d8c1]::query::caches::SingleCache<rustc_middle[f0eb6ba890d0a9bb]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[1357963d8dd30e8b]::plumbing::QueryCtxt, false>
  28:     0x7fde36f929ce - rustc_query_impl[1357963d8dd30e8b]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  29:     0x7fde36e8707a - rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler::<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}
  30:     0x7fde36ecd5d0 - std[56fe22ad9ea837fd]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>
  31:     0x7fde36ecd9eb - <<std[56fe22ad9ea837fd]::thread::Builder>::spawn_unchecked_<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_with_globals<rustc_interface[5fea8bf9cd0b71b5]::util::run_in_thread_pool_with_globals<rustc_interface[5fea8bf9cd0b71b5]::interface::run_compiler<core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>, rustc_driver_impl[945e9afaf49c7d35]::run_compiler::{closure#0}>::{closure#1}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5ba82ee3405aa490]::result::Result<(), rustc_span[db86d96c2ae2e3a4]::ErrorGuaranteed>>::{closure#1} as core[5ba82ee3405aa490]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  32:     0x7fde36ece4b9 - std::sys::pal::unix::thread::Thread::new::thread_start::hb3d6392adeea417c
  33:     0x7fde3106bac3 - start_thread
                               at ./nptl/pthread_create.c:442:8
  34:     0x7fde310fd850 - __GI___clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  35:                0x0 - <unknown>

Anything else

Could this be related to #120267?

[wxie7]

This one as well

use std::hint::black_box;
trait Func {
    type Ret: Id;
}
trait Id {
    type Assoc;
}
impl Id for u32 {
    type Assoc = u32;
}
impl Id for i32 {
    type Assoc = i32;
}
impl<F: FnOnce() -> R, R: Id> Func for F {
    type Ret = R;
}
fn bar() -> impl Copy + Id {
    Box::new([1; 1])
}
struct Foo<T: Func> {
    _func: T,
    value: Option<<<T as Func>::Ret as Id>::Assoc>,
}
fn main() {
    let mut fn_def = black_box(Foo {
        _func: bar,
        value: None,
    });
    let fn_ptr = black_box(Foo {
        _func: bar as fn() -> _,
        value: None,
    });
    fn_def.value = fn_ptr.value;
    black_box(fn_def);
}

[cyrgani]

Slightly reduced:

trait Func {
    type Ret;
}
impl<F: FnOnce() -> R, R> Func for F {
    type Ret = R;
}

trait Id {}
fn invalid_impl_trait() -> impl Id {}

struct Foo<T: Func> {
    _func: T,
    value: Option<<T as Func>::Ret>,
}

fn main() {
    let foo = Foo {
        _func: invalid_impl_trait,
        value: None,
    };
    drop(foo.value);
}

[compiler-errors]

Hi @wxie7 -- if you're going to try to fuzz the test suite, please clearly indicate that you derived this from a test, and please try your best to minimize it significantly past the input you derived it from. I think it's bad style to have many copies of slightly tweaked tests, when this is almost certainly due to an issue that is much smaller than the repro that you've provided.