ICE: panicked at /rust/deps/stacker-0.1.17/src/lib.rs:197:21, The ICE message has not ended.

[wxie7]

I tried this code:

# ! [ feature ( type_alias_impl_trait ) ]
trait Id {
type Assoc ;
}
impl < T > T {
Assoc = T ;
}
type Ty
where
Ty : Id < Assoc = Ty > ,
= impl Sized ;
fn define ( ) -> Ty { }
fn main ( ) { }

It mutates from the following file, but the following code will not cause a ICE.

Also, I used type_alias_impl_trait and Assoc as search keywords but didn’t find any related issues with open.

#![feature(type_alias_impl_trait)]

trait Id {
    type Assoc;
}
impl<T> Id for T {
    type Assoc = T;
}

type Ty
where
    Ty: Id<Assoc = Ty>,
= impl Sized;
fn define() -> Ty {}
fn main() {}

Meta

rustc --version --verbose:

rustc 1.85.0-nightly (acabb5248 2024-12-04)
binary: rustc
commit-hash: acabb5248231987ae1f0c215208d1005a5db402d
commit-date: 2024-12-04
host: x86_64-unknown-linux-gnu
release: 1.85.0-nightly
LLVM version: 19.1.5

Part of the ICE information is as follows:

Backtrace

   |
2  | trait Id {
   | ^^^^^^^^
note: required by a bound on the type alias `Ty`
  --> mutant.rs:10:6
   |
10 | Ty : Id < Assoc = Ty > ,
   |      ^^^^^^^^^^^^^^^^^ required by this bound

error[E0118]: no nominal type found for inherent implementation
 --> mutant.rs:5:1
  |
5 | impl < T > T {
  | ^^^^^^^^^^^^ impl requires a nominal type
  |
  = note: either implement a trait on it or create a newtype to wrap it instead

thread 'rustc' panicked at /rust/deps/stacker-0.1.17/src/lib.rs:197:21:
setting stack permissions failed with: Cannot allocate memory (os error 12)
stack backtrace:
   0:     0x7dbef8b3c5ba - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h0ab6de9a9b46b
   1:     0x7dbef9213e66 - core::fmt::write::h786572316278241a
   2:     0x7dbefa1d1a51 - std::io::Write::write_fmt::h253c21bff6dc1068
   3:     0x7dbef8b3c412 - std::sys::backtrace::BacktraceLock::print::h72ad191a9e5c3f0c
   4:     0x7dbef8b3e93a - std::panicking::default_hook::{{closure}}::h697ead15ac8858f2
   5:     0x7dbef8b3e783 - std::panicking::default_hook::h36df36946face91c
   6:     0x7dbef7cb9318 - std[72a4a0de9fece711]::panicking::update_hook::<alloc[272e4c5910fec5b6]::boxed::Box<rustc_driver_impl[e7
   7:     0x7dbef8b3f0f8 - std::panicking::rust_panic_with_hook::h66ac57f6f29fdfbd
   8:     0x7dbef8b3edea - std::panicking::begin_panic_handler::{{closure}}::h44ac1fccfa946230
   9:     0x7dbef8b3ca79 - std::sys::backtrace::__rust_end_short_backtrace::ha74a12e03dbbea79
  10:     0x7dbef8b3eaad - rust_begin_unwind
  11:     0x7dbef57ae100 - core::panicking::panic_fmt::hed29c46432bb0866
  12:     0x7dbef7666836 - stacker[b47ad8164a60aea4]::_grow
  13:     0x7dbefa695a33 - rustc_trait_selection[8a5c83665fe794d1]::traits::normalize::normalize_with_depth_to::<rustc_type_ir[b72b
  14:     0x7dbef9cbdad3 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_re
  15:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursiv
  16:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_re
  17:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursiv
  18:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_re
  19:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursiv
  20:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_re
  21:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursiv
  22:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_re
  23:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursiv
  24:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_re
  25:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursiv
  26:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_re
  27:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursively
  28:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  29:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursively
  30:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  31:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursively
  32:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  33:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursively
  34:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively
  35:     0x7dbef9caf015 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_predicate_recursively
  36:     0x7dbef9cbf344 - <rustc_trait_selection[8a5c83665fe794d1]::traits::select::SelectionContext>::evaluate_trait_predicate_recursively

[jieyouxu]

setting stack permissions failed with: Cannot allocate memory (os error 12)

[jieyouxu]

Feature not required, parse error removed, seems to hang on stable too

trait Id {
    type Assoc;
}

impl<T> T {
    type Assoc = T ;
}

type Ty where Ty: Id<Assoc = Ty> = impl Sized;

fn define() -> Ty {}

fn main() {}

However this seems to still involve TAIT, even though the feature gate was not active.

[jieyouxu]

This is a duplicate of an issue you already reported at #132797.

[wxie7]

Maybe I should modify the search strategy...

[jieyouxu]

@wxie7 It can be hard to find the exact issues sometimes, some things you can try include:

• Searching for the key parts of the backtrace
• Looking for open issues labeled with the same F-*
• Looking for the relevant A-* labels, but this may require some compiler knowledge

I didn't find the original issue either without having produced the MCVE, which is why having a smaller yet still repro-ing example is so important.