Repository: rust
Issue: ICE: `parent item: DefId(0:5 ~ a[9a36]::{impl#1}) not marked as default`
Labels: I-ICE,P-low,T-compiler,C-bug,F-const_trait_impl,F-effects,F-min_specialization

<!--
[31mICE[0m: Rustc ./a.rs '-Zcrate-attr=feature(min_specialization) -ooutputfile -Zdump-mir-dir=dir' 'error: internal compiler error: parent item: DefId(0:5 ~ a[9a36]::{impl#1}) not marked as default', 'error: internal compiler error: parent item: DefId(0:5 ~ a[9a36]::{impl#1}) not marked as default'
File: /tmp/im/a.rs
-->

auto-reduced (treereduce-rust):
````rust
#![feature(const_trait_impl, effects, min_specialization)]

#[const_trait]
trait Foo {}

impl const Foo for i32 {}

impl<T> const Foo for T {}

fn main() {}

````

original:
````rust
#![allow(incomplete_features)]
#![feature(const_trait_impl, effects)]

#[const_trait]
trait Foo {}

impl const Foo for i32 {}

impl<T> const Foo for T where T: std::ops::Add {}
//~^ ERROR conflicting implementations of trait `Foo` for type `i32`

fn main() {}

````

Version information
````
rustc 1.81.0-nightly (ba1d7f4a0 2024-06-29)
binary: rustc
commit-hash: ba1d7f4a083e6402679105115ded645512a7aea8
commit-date: 2024-06-29
host: x86_64-unknown-linux-gnu
release: 1.81.0-nightly
LLVM version: 18.1.7

````

Command:
`/home/matthias/.rustup/toolchains/master/bin/rustc -Zcrate-attr=feature(min_specialization)`

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<details><summary><strong>Program output</strong></summary>
<p>

```
warning: the feature `effects` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /tmp/icemaker_global_tempdir.c0RYNwyTFenY/rustc_testrunner_tmpdir_reporting.7X6MiHL6JNkS/mvce.rs:1:30
  |
1 | #![feature(const_trait_impl, effects)]
  |                              ^^^^^^^
  |
  = note: see issue #102090 <https://github.com/rust-lang/rust/issues/102090> for more information
  = note: `#[warn(incomplete_features)]` on by default

warning: trait `Foo` is never used
 --> /tmp/icemaker_global_tempdir.c0RYNwyTFenY/rustc_testrunner_tmpdir_reporting.7X6MiHL6JNkS/mvce.rs:4:7
  |
4 | trait Foo {}
  |       ^^^
  |
  = note: `#[warn(dead_code)]` on by default

warning: 2 warnings emitted

note: no errors encountered even though delayed bugs were created

note: those delayed bugs will now be shown as internal compiler errors

error: internal compiler error: parent item: DefId(0:5 ~ mvce[9951]::{impl#1}) not marked as default
  |
  = note: delayed at compiler/rustc_hir_analysis/src/check/check.rs:886:23 - disabled backtrace

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: please make sure that you have updated to the latest nightly

note: rustc 1.81.0-nightly (ba1d7f4a0 2024-06-29) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z crate-attr=feature(min_specialization) -Z dump-mir-dir=dir

query stack during panic:
end of query stack

```

</p>
</details>

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@rustbot label +F-const_trait_impl +F-effects +F-min_specialization