ICE: `inference variables in normalized parameter environment: unconstrained type`

[matthiaskrgr]

snippet:

#![feature(non_lifetime_binders)]

pub trait Foo<T: ?Sized> {
    type Bar<K: ?Sized>;
}

pub struct Bar<T: ?AutoTrait> {}

pub fn f<T1, T2>()
where
    T1: for<T> Foo<usize, Bar = Bar<T>>,
    T2: for<L, T> Foo<usize, Bar<T> = T1::Bar<T>>,
{
}

Version information

rustc 1.77.0-nightly (e64f8495e 2024-01-16)
binary: rustc
commit-hash: e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d
commit-date: 2024-01-16
host: x86_64-unknown-linux-gnu
release: 1.77.0-nightly
LLVM version: 17.0.6

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

error[E0405]: cannot find trait `AutoTrait` in this scope
 --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:7:20
  |
7 | pub struct Bar<T: ?AutoTrait> {}
  |                    ^^^^^^^^^ not found in this scope

warning: the feature `non_lifetime_binders` is incomplete and may not be safe to use and/or cause compiler crashes
 --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:1:12
  |
1 | #![feature(non_lifetime_binders)]
  |            ^^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information
  = note: `#[warn(incomplete_features)]` on by default

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:14:2
   |
14 | }
   |  ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs`

warning: relaxing a default bound only does something for `?Sized`; all other traits are not bound by default
 --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:7:19
  |
7 | pub struct Bar<T: ?AutoTrait> {}
  |                   ^^^^^^^^^^

error[E0107]: missing generics for associated type `Foo::Bar`
  --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:11:27
   |
11 |     T1: for<T> Foo<usize, Bar = Bar<T>>,
   |                           ^^^ expected 1 generic argument
   |
note: associated type defined here, with 1 generic parameter: `K`
  --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:4:10
   |
4  |     type Bar<K: ?Sized>;
   |          ^^^ -
help: add missing generic argument
   |
11 |     T1: for<T> Foo<usize, Bar<K> = Bar<T>>,
   |                              +++

error[E0392]: parameter `T` is never used
 --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:7:16
  |
7 | pub struct Bar<T: ?AutoTrait> {}
  |                ^ unused parameter
  |
  = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData`

error: internal compiler error: compiler/rustc_trait_selection/src/traits/mod.rs:236:13: inference variables in normalized parameter environment: unconstrained type
  --> /tmp/icemaker_global_tempdir.sRdilPN7rXO6/rustc_testrunner_tmpdir_reporting.ngEGvTdeSLNZ/mvce.rs:9:1
   |
9  | / pub fn f<T1, T2>()
10 | | where
11 | |     T1: for<T> Foo<usize, Bar = Bar<T>>,
12 | |     T2: for<L, T> Foo<usize, Bar<T> = T1::Bar<T>>,
   | |__________________________________________________^

thread 'rustc' panicked at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/compiler/rustc_errors/src/lib.rs:854:41:
Box<dyn Any>
stack backtrace:
   0:     0x7f0cd5817806 - std::backtrace_rs::backtrace::libunwind::trace::h4b22376ba0492652
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
   1:     0x7f0cd5817806 - std::backtrace_rs::backtrace::trace_unsynchronized::h0e3835b8afb2038f
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f0cd5817806 - std::sys_common::backtrace::_print_fmt::h01e8ef90ace289e3
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7f0cd5817806 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hf9dd6cae74685c81
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f0cd5869e00 - core::fmt::rt::Argument::fmt::h8ea94010f89e6634
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/core/src/fmt/rt.rs:142:9
   5:     0x7f0cd5869e00 - core::fmt::write::h72cc333598639a69
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/core/src/fmt/mod.rs:1120:17
   6:     0x7f0cd580b1cf - std::io::Write::write_fmt::h4b8808e44803d04e
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/io/mod.rs:1810:15
   7:     0x7f0cd58175e4 - std::sys_common::backtrace::_print::hb2c185826855226e
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f0cd58175e4 - std::sys_common::backtrace::print::hf0402097dc954189
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f0cd581a377 - std::panicking::default_hook::{{closure}}::h2879d7f688c03513
  10:     0x7f0cd581a0d9 - std::panicking::default_hook::h6b4d39921063eece
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/panicking.rs:292:9
  11:     0x7f0cd2567b4c - std[45f158bc17f9e196]::panicking::update_hook::<alloc[f6bf7dd499ada734]::boxed::Box<rustc_driver_impl[856b55f1ad5b32fc]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7f0cd581aac6 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hbefca42bded875fc
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/alloc/src/boxed.rs:2030:9
  13:     0x7f0cd581aac6 - std::panicking::rust_panic_with_hook::h861adc023e7cc0c9
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/panicking.rs:785:13
  14:     0x7f0cd2599ab4 - std[45f158bc17f9e196]::panicking::begin_panic::<rustc_errors[9a83f08cfa696d6d]::ExplicitBug>::{closure#0}
  15:     0x7f0cd2596076 - std[45f158bc17f9e196]::sys_common::backtrace::__rust_end_short_backtrace::<std[45f158bc17f9e196]::panicking::begin_panic<rustc_errors[9a83f08cfa696d6d]::ExplicitBug>::{closure#0}, !>
  16:     0x7f0cd2591136 - std[45f158bc17f9e196]::panicking::begin_panic::<rustc_errors[9a83f08cfa696d6d]::ExplicitBug>
  17:     0x7f0cd25a4c51 - <rustc_errors[9a83f08cfa696d6d]::diagnostic_builder::BugAbort as rustc_errors[9a83f08cfa696d6d]::diagnostic_builder::EmissionGuarantee>::emit_producing_guarantee
  18:     0x7f0cd2fbbb8d - rustc_middle[eb670d4eb5009434]::util::bug::opt_span_bug_fmt::<rustc_span[1828e6de90cfe8a6]::span_encoding::Span>::{closure#0}
  19:     0x7f0cd2fbbbba - rustc_middle[eb670d4eb5009434]::ty::context::tls::with_opt::<rustc_middle[eb670d4eb5009434]::util::bug::opt_span_bug_fmt<rustc_span[1828e6de90cfe8a6]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  20:     0x7f0cd2f8f0e8 - rustc_middle[eb670d4eb5009434]::ty::context::tls::with_context_opt::<rustc_middle[eb670d4eb5009434]::ty::context::tls::with_opt<rustc_middle[eb670d4eb5009434]::util::bug::opt_span_bug_fmt<rustc_span[1828e6de90cfe8a6]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  21:     0x7f0cd2f8c1f4 - rustc_middle[eb670d4eb5009434]::util::bug::span_bug_fmt::<rustc_span[1828e6de90cfe8a6]::span_encoding::Span>
  22:     0x7f0cd4199627 - rustc_trait_selection[bc7c8cde1afc0761]::traits::do_normalize_predicates
  23:     0x7f0cd3f786da - rustc_trait_selection[bc7c8cde1afc0761]::traits::normalize_param_env_or_error
  24:     0x7f0cd3ac9eb4 - rustc_ty_utils[a1af397cf76d45e7]::ty::param_env
  25:     0x7f0cd3ac9a59 - rustc_query_impl[a4ba8400aa2b99d0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a4ba8400aa2b99d0]::query_impl::param_env::dynamic_query::{closure#2}::{closure#0}, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 8usize]>>
  26:     0x7f0cd389cfd4 - rustc_query_system[1dd2241d09e5cc4c]::query::plumbing::try_execute_query::<rustc_query_impl[a4ba8400aa2b99d0]::DynamicConfig<rustc_query_system[1dd2241d09e5cc4c]::query::caches::DefaultCache<rustc_span[1828e6de90cfe8a6]::def_id::DefId, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[a4ba8400aa2b99d0]::plumbing::QueryCtxt, false>
  27:     0x7f0cd389cae1 - rustc_query_impl[a4ba8400aa2b99d0]::query_impl::param_env::get_query_non_incr::__rust_end_short_backtrace
  28:     0x7f0cd3c275a8 - rustc_middle[eb670d4eb5009434]::query::plumbing::query_get_at::<rustc_query_system[1dd2241d09e5cc4c]::query::caches::DefaultCache<rustc_span[1828e6de90cfe8a6]::def_id::DefId, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 8usize]>>>
  29:     0x7f0cd3c3740e - rustc_hir_analysis[9d00e3e5b40bb3cf]::check::wfcheck::check_item_fn
  30:     0x7f0cd3c34e2d - rustc_hir_analysis[9d00e3e5b40bb3cf]::check::wfcheck::check_well_formed
  31:     0x7f0cd3c33b2f - rustc_query_impl[a4ba8400aa2b99d0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a4ba8400aa2b99d0]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 1usize]>>
  32:     0x7f0cd3c3320b - rustc_query_system[1dd2241d09e5cc4c]::query::plumbing::try_execute_query::<rustc_query_impl[a4ba8400aa2b99d0]::DynamicConfig<rustc_query_system[1dd2241d09e5cc4c]::query::caches::VecCache<rustc_hir[5d84c8f70b537736]::hir_id::OwnerId, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a4ba8400aa2b99d0]::plumbing::QueryCtxt, false>
  33:     0x7f0cd3c32f83 - rustc_query_impl[a4ba8400aa2b99d0]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
  34:     0x7f0cd3c309b7 - rustc_hir_analysis[9d00e3e5b40bb3cf]::check::wfcheck::check_mod_type_wf
  35:     0x7f0cd3c308fb - rustc_query_impl[a4ba8400aa2b99d0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a4ba8400aa2b99d0]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 1usize]>>
  36:     0x7f0cd3c2fa95 - rustc_query_system[1dd2241d09e5cc4c]::query::plumbing::try_execute_query::<rustc_query_impl[a4ba8400aa2b99d0]::DynamicConfig<rustc_query_system[1dd2241d09e5cc4c]::query::caches::DefaultCache<rustc_span[1828e6de90cfe8a6]::def_id::LocalModDefId, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a4ba8400aa2b99d0]::plumbing::QueryCtxt, false>
  37:     0x7f0cd3c2f843 - rustc_query_impl[a4ba8400aa2b99d0]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
  38:     0x7f0cd3e982b0 - <rustc_middle[eb670d4eb5009434]::hir::map::Map>::try_par_for_each_module::<rustc_hir_analysis[9d00e3e5b40bb3cf]::check_crate::{closure#4}::{closure#0}>::{closure#0}
  39:     0x7f0cd3e96611 - rustc_hir_analysis[9d00e3e5b40bb3cf]::check_crate
  40:     0x7f0cd427e819 - rustc_interface[13fabbb621f7a7a7]::passes::analysis
  41:     0x7f0cd427e45f - rustc_query_impl[a4ba8400aa2b99d0]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[a4ba8400aa2b99d0]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 1usize]>>
  42:     0x7f0cd47a65a4 - rustc_query_system[1dd2241d09e5cc4c]::query::plumbing::try_execute_query::<rustc_query_impl[a4ba8400aa2b99d0]::DynamicConfig<rustc_query_system[1dd2241d09e5cc4c]::query::caches::SingleCache<rustc_middle[eb670d4eb5009434]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[a4ba8400aa2b99d0]::plumbing::QueryCtxt, false>
  43:     0x7f0cd47a6395 - rustc_query_impl[a4ba8400aa2b99d0]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  44:     0x7f0cd45463ad - rustc_interface[13fabbb621f7a7a7]::interface::run_compiler::<core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>, rustc_driver_impl[856b55f1ad5b32fc]::run_compiler::{closure#0}>::{closure#0}
  45:     0x7f0cd4808e46 - std[45f158bc17f9e196]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[13fabbb621f7a7a7]::util::run_in_thread_with_globals<rustc_interface[13fabbb621f7a7a7]::util::run_in_thread_pool_with_globals<rustc_interface[13fabbb621f7a7a7]::interface::run_compiler<core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>, rustc_driver_impl[856b55f1ad5b32fc]::run_compiler::{closure#0}>::{closure#0}, core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>>::{closure#0}, core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>>
  46:     0x7f0cd4808c73 - <<std[45f158bc17f9e196]::thread::Builder>::spawn_unchecked_<rustc_interface[13fabbb621f7a7a7]::util::run_in_thread_with_globals<rustc_interface[13fabbb621f7a7a7]::util::run_in_thread_pool_with_globals<rustc_interface[13fabbb621f7a7a7]::interface::run_compiler<core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>, rustc_driver_impl[856b55f1ad5b32fc]::run_compiler::{closure#0}>::{closure#0}, core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>>::{closure#0}, core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[5977124cf3f69ab]::result::Result<(), rustc_span[1828e6de90cfe8a6]::ErrorGuaranteed>>::{closure#1} as core[5977124cf3f69ab]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  47:     0x7f0cd58243b5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h5d9d7f54a2e59c6d
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/alloc/src/boxed.rs:2016:9
  48:     0x7f0cd58243b5 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h48bf4b2427be9cd8
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/alloc/src/boxed.rs:2016:9
  49:     0x7f0cd58243b5 - std::sys::pal::unix::thread::Thread::new::thread_start::hbf0f1ac511c22d9d
                               at /rustc/e64f8495e73fbc3653b4bcb73268c58b9c4a0a0d/library/std/src/sys/pal/unix/thread.rs:108:17
  50:     0x7f0ccf6aa9eb - <unknown>
  51:     0x7f0ccf72e7cc - <unknown>
  52:                0x0 - <unknown>

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 1.77.0-nightly (e64f8495e 2024-01-16) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [param_env] computing normalized predicates of `f`
#1 [check_well_formed] checking that `f` is well-formed
#2 [check_mod_type_wf] checking that types are well-formed in top-level module
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 5 previous errors; 2 warnings emitted

Some errors have detailed explanations: E0107, E0392, E0405, E0601.
For more information about an error, try `rustc --explain E0107`.

[matthiaskrgr]

#117449 cc @oli-obk 😅

[matthiaskrgr]

probably related, does not require non-lifetime-binders: inference variables in normalized parameter environment: unconstrained const value

auto-reduced (treereduce-rust):

trait Archive {
    type Archived;
}

type Archived<T> = <T as Archive>::Archived;

trait Deserialize<T: Archive, T: Archive> {}

impl<T, const N: usize> Archive for [T; B]
where
    T: Archive,
{
    type Archived = [T::Archived; N];
}

pub const MYSIZE: usize = 10;

impl<T> Archive for Sad<T>
where
    T: Archive,
    Archived<[T; MYSIZE]>: Deserialize<[T; MYSIZE], D>,
    T::Archived:,
{
}

original code

original:

// Traits and base impls:
trait Archive {
    type Archived;
}

type Archived<T> = <T as Archive>::Archived;

trait Deserialize<T: Archive, T: Archive> {}

impl<T, const N: usize> Archive for [T; B]
where
    T: Archive,
{
    type Archived = [T::Archived; N];
}

impl<T: Archive, D: ?Sized, const N: usize> Deserialize<[T; N], D> for [T::Archived; N]
where
    T: Archive,
    T::Archived: Deserialize<T, D>,
{
}

// A happy struct + impls that works perfectly fine:
pub enum Happy<T> {
    A([T; 10]),
    B([T; 10]),
}

impl<T> Archive for Happy<T>
where
    T: Archive,
    [T; 10]: Archive,
    [T; 10]: Archive,
{
    type Archived = Happy<Archived<T>>;
}

impl<D: ?Sized, T> Deserialize<Happy<T>, D> for Archived<Happy<T>>
where
    T: Archive,
    [T; 10]: Archive,
    Archived<[T; 10]>: Deserialize<[T; 10], D>,
    [T; 10]: Archive,
    Archived<[T; 10]>: Deserialize<[T; 10], D>,
{
}

// A sad struct + impls that causes a compiler error:
pub const MYSIZE: usize = 10;

pub enum Sad<T> {
    A([T; MYSIZE]),
    B([T; MYSIZE]),
}

impl<T> Archive for Sad<T>
where
    T: Archive,
    Archived<[T; MYSIZE]>: Deserialize<[T; MYSIZE], D>,
    T::Archived: Deserialize<T, D>,
{
    type Archived = Sad<Archived<T>>;
}

impl<D: ?Sized, T> Deserialize<Sad<T>, D> for Archived<Sad<T>>
where
    T: Archive,
    Archived<[T; 10]>: Deserialize<[T; 10], D>,
    Archived<[T; MYSIZE]>: Deserialize<[T; MYSIZE], D>,
    [T; MYSIZE]: Archive,                               // 💣
    Archived<[T; MYSIZE]>: Deserialize<[T; MYSIZE], D>, // 💣
{
}

Version information

rustc 1.80.0-nightly (91d5e4af8 2024-04-28)
binary: rustc
commit-hash: 91d5e4af8674bde06096bac1e7ac04af0e94c691
commit-date: 2024-04-28
host: x86_64-unknown-linux-gnu
release: 1.80.0-nightly
LLVM version: 18.1.4

Command:
/home/matthias/.rustup/toolchains/master/bin/rustc

Program output

error[E0403]: the name `T` is already used for a generic parameter in this item's generic parameters
 --> /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:7:31
  |
7 | trait Deserialize<T: Archive, T: Archive> {}
  |                   -           ^ already used
  |                   |
  |                   first use of `T`

error[E0425]: cannot find value `B` in this scope
 --> /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:9:41
  |
9 | impl<T, const N: usize> Archive for [T; B]
  |               -                         ^ help: a const parameter with a similar name exists: `N`
  |               |
  |               similarly named const parameter `N` defined here

error[E0412]: cannot find type `Sad` in this scope
  --> /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:18:21
   |
18 | impl<T> Archive for Sad<T>
   |                     ^^^ not found in this scope

error[E0412]: cannot find type `D` in this scope
  --> /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:21:53
   |
18 | impl<T> Archive for Sad<T>
   |      - similarly named type parameter `T` defined here
...
21 |     Archived<[T; MYSIZE]>: Deserialize<[T; MYSIZE], D>,
   |                                                     ^
   |
help: a type parameter with a similar name exists
   |
21 |     Archived<[T; MYSIZE]>: Deserialize<[T; MYSIZE], T>,
   |                                                     ~
help: you might be missing a type parameter
   |
18 | impl<T, D> Archive for Sad<T>
   |       +++

error[E0601]: `main` function not found in crate `mvce`
  --> /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:24:2
   |
24 | }
   |  ^ consider adding a `main` function to `/tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs`

error[E0207]: the const parameter `N` is not constrained by the impl trait, self type, or predicates
 --> /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:9:9
  |
9 | impl<T, const N: usize> Archive for [T; B]
  |         ^^^^^^^^^^^^^^ unconstrained const parameter
  |
  = note: expressions using a const parameter must map each value to a distinct output value
  = note: proving the result of expressions other than the parameter are unique is not supported

error: internal compiler error: compiler/rustc_trait_selection/src/traits/mod.rs:237:13: inference variables in normalized parameter environment: unconstrained const value
  --> /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:18:1
   |
18 | / impl<T> Archive for Sad<T>
19 | | where
20 | |     T: Archive,
21 | |     Archived<[T; MYSIZE]>: Deserialize<[T; MYSIZE], D>,
22 | |     T::Archived:,
   | |_________________^

thread 'rustc' panicked at compiler/rustc_trait_selection/src/traits/mod.rs:237:13:
Box<dyn Any>
stack backtrace:
   0:     0x7042d8170035 - std::backtrace_rs::backtrace::libunwind::trace::ha90ea7a57c64b8ab
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/../../backtrace/src/backtrace/libunwind.rs:105:5
   1:     0x7042d8170035 - std::backtrace_rs::backtrace::trace_unsynchronized::ha58e55f622939b6e
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7042d8170035 - std::sys_common::backtrace::_print_fmt::h687007ed504e7e64
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/sys_common/backtrace.rs:68:5
   3:     0x7042d8170035 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hecfae54cdc6fec81
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7042d81bf29b - core::fmt::rt::Argument::fmt::h1cf6305de42401ed
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/core/src/fmt/rt.rs:165:63
   5:     0x7042d81bf29b - core::fmt::write::hb74fc275648248fb
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/core/src/fmt/mod.rs:1157:21
   6:     0x7042d8164bdf - std::io::Write::write_fmt::h5209ffd8e6502f0c
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/io/mod.rs:1832:15
   7:     0x7042d816fe0e - std::sys_common::backtrace::_print::h168707047d27c84e
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7042d816fe0e - std::sys_common::backtrace::print::h2942d174d6b0e46d
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7042d8172779 - std::panicking::default_hook::{{closure}}::h4215c46ca923b014
  10:     0x7042d81724bd - std::panicking::default_hook::h887f937d01fa1b64
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/panicking.rs:298:9
  11:     0x7042d4a40a1c - std[aaff33ccdb7ea7e2]::panicking::update_hook::<alloc[d1c3a5de2ae3927d]::boxed::Box<rustc_driver_impl[d0a4257edbfecd8c]::install_ice_hook::{closure#0}>>::{closure#0}
  12:     0x7042d8172e76 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::hfe27c2dc23f9f057
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/alloc/src/boxed.rs:2036:9
  13:     0x7042d8172e76 - std::panicking::rust_panic_with_hook::h6ef218c13552449b
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/panicking.rs:799:13
  14:     0x7042d4a70374 - std[aaff33ccdb7ea7e2]::panicking::begin_panic::<rustc_errors[6ff9940fea39db99]::ExplicitBug>::{closure#0}
  15:     0x7042d4a6cff6 - std[aaff33ccdb7ea7e2]::sys_common::backtrace::__rust_end_short_backtrace::<std[aaff33ccdb7ea7e2]::panicking::begin_panic<rustc_errors[6ff9940fea39db99]::ExplicitBug>::{closure#0}, !>
  16:     0x7042d4a6ccd6 - std[aaff33ccdb7ea7e2]::panicking::begin_panic::<rustc_errors[6ff9940fea39db99]::ExplicitBug>
  17:     0x7042d4a79181 - <rustc_errors[6ff9940fea39db99]::diagnostic::BugAbort as rustc_errors[6ff9940fea39db99]::diagnostic::EmissionGuarantee>::emit_producing_guarantee
  18:     0x7042d54c8d78 - <rustc_errors[6ff9940fea39db99]::DiagCtxt>::span_bug::<rustc_span[6a84a2dd20c85103]::span_encoding::Span, alloc[d1c3a5de2ae3927d]::string::String>
  19:     0x7042d5511fcd - rustc_middle[783a1d49f02736b7]::util::bug::opt_span_bug_fmt::<rustc_span[6a84a2dd20c85103]::span_encoding::Span>::{closure#0}
  20:     0x7042d551219a - rustc_middle[783a1d49f02736b7]::ty::context::tls::with_opt::<rustc_middle[783a1d49f02736b7]::util::bug::opt_span_bug_fmt<rustc_span[6a84a2dd20c85103]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7042d54e9c0b - rustc_middle[783a1d49f02736b7]::ty::context::tls::with_context_opt::<rustc_middle[783a1d49f02736b7]::ty::context::tls::with_opt<rustc_middle[783a1d49f02736b7]::util::bug::opt_span_bug_fmt<rustc_span[6a84a2dd20c85103]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7042d54e8f07 - rustc_middle[783a1d49f02736b7]::util::bug::span_bug_fmt::<rustc_span[6a84a2dd20c85103]::span_encoding::Span>
  23:     0x7042d60730b8 - rustc_trait_selection[55c49d40a157c509]::traits::do_normalize_predicates
  24:     0x7042d2f2ed4e - rustc_trait_selection[55c49d40a157c509]::traits::normalize_param_env_or_error
  25:     0x7042d5e90b8b - rustc_ty_utils[a96e7d9f6f95dd10]::ty::param_env
  26:     0x7042d5e907d7 - rustc_query_impl[77a161a94332e7e1]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77a161a94332e7e1]::query_impl::param_env::dynamic_query::{closure#2}::{closure#0}, rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 8usize]>>
  27:     0x7042d5e94f8e - rustc_query_system[61cd216fcfa07925]::query::plumbing::try_execute_query::<rustc_query_impl[77a161a94332e7e1]::DynamicConfig<rustc_query_system[61cd216fcfa07925]::query::caches::DefIdCache<rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[77a161a94332e7e1]::plumbing::QueryCtxt, false>
  28:     0x7042d5e949db - rustc_query_impl[77a161a94332e7e1]::query_impl::param_env::get_query_non_incr::__rust_end_short_backtrace
  29:     0x7042d646072f - rustc_hir_analysis[52d62df79dc1fb71]::check::wfcheck::check_well_formed
  30:     0x7042d645ffad - rustc_query_impl[77a161a94332e7e1]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77a161a94332e7e1]::query_impl::check_well_formed::dynamic_query::{closure#2}::{closure#0}, rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 1usize]>>
  31:     0x7042d645f740 - rustc_query_system[61cd216fcfa07925]::query::plumbing::try_execute_query::<rustc_query_impl[77a161a94332e7e1]::DynamicConfig<rustc_query_system[61cd216fcfa07925]::query::caches::VecCache<rustc_hir[353c6e3d6d4db717]::hir_id::OwnerId, rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[77a161a94332e7e1]::plumbing::QueryCtxt, false>
  32:     0x7042d645f4bf - rustc_query_impl[77a161a94332e7e1]::query_impl::check_well_formed::get_query_non_incr::__rust_end_short_backtrace
  33:     0x7042d645d437 - rustc_hir_analysis[52d62df79dc1fb71]::check::wfcheck::check_mod_type_wf
  34:     0x7042d645d267 - rustc_query_impl[77a161a94332e7e1]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77a161a94332e7e1]::query_impl::check_mod_type_wf::dynamic_query::{closure#2}::{closure#0}, rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 1usize]>>
  35:     0x7042d6be8b70 - rustc_query_system[61cd216fcfa07925]::query::plumbing::try_execute_query::<rustc_query_impl[77a161a94332e7e1]::DynamicConfig<rustc_query_system[61cd216fcfa07925]::query::caches::DefaultCache<rustc_span[6a84a2dd20c85103]::def_id::LocalModDefId, rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[77a161a94332e7e1]::plumbing::QueryCtxt, false>
  36:     0x7042d6be891b - rustc_query_impl[77a161a94332e7e1]::query_impl::check_mod_type_wf::get_query_non_incr::__rust_end_short_backtrace
  37:     0x7042d61a08d3 - rustc_hir_analysis[52d62df79dc1fb71]::check_crate
  38:     0x7042d61827c7 - rustc_interface[3360209938edb6a7]::passes::analysis
  39:     0x7042d6182315 - rustc_query_impl[77a161a94332e7e1]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[77a161a94332e7e1]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 1usize]>>
  40:     0x7042d6bffba5 - rustc_query_system[61cd216fcfa07925]::query::plumbing::try_execute_query::<rustc_query_impl[77a161a94332e7e1]::DynamicConfig<rustc_query_system[61cd216fcfa07925]::query::caches::SingleCache<rustc_middle[783a1d49f02736b7]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[77a161a94332e7e1]::plumbing::QueryCtxt, false>
  41:     0x7042d6bff909 - rustc_query_impl[77a161a94332e7e1]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  42:     0x7042d6aa328e - rustc_interface[3360209938edb6a7]::interface::run_compiler::<core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>, rustc_driver_impl[d0a4257edbfecd8c]::run_compiler::{closure#0}>::{closure#1}
  43:     0x7042d6a727c9 - std[aaff33ccdb7ea7e2]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[3360209938edb6a7]::util::run_in_thread_with_globals<rustc_interface[3360209938edb6a7]::util::run_in_thread_pool_with_globals<rustc_interface[3360209938edb6a7]::interface::run_compiler<core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>, rustc_driver_impl[d0a4257edbfecd8c]::run_compiler::{closure#0}>::{closure#1}, core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>>::{closure#0}, core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>>
  44:     0x7042d6a72576 - <<std[aaff33ccdb7ea7e2]::thread::Builder>::spawn_unchecked_<rustc_interface[3360209938edb6a7]::util::run_in_thread_with_globals<rustc_interface[3360209938edb6a7]::util::run_in_thread_pool_with_globals<rustc_interface[3360209938edb6a7]::interface::run_compiler<core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>, rustc_driver_impl[d0a4257edbfecd8c]::run_compiler::{closure#0}>::{closure#1}, core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>>::{closure#0}, core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[8db7010e98043ac]::result::Result<(), rustc_span[6a84a2dd20c85103]::ErrorGuaranteed>>::{closure#2} as core[8db7010e98043ac]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  45:     0x7042d817ccab - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h1c1c6804813d5e77
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/alloc/src/boxed.rs:2022:9
  46:     0x7042d817ccab - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h3d84aa3b40a67b8f
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/alloc/src/boxed.rs:2022:9
  47:     0x7042d817ccab - std::sys::pal::unix::thread::Thread::new::thread_start::h60cefba2ee6cce64
                               at /rustc/91d5e4af8674bde06096bac1e7ac04af0e94c691/library/std/src/sys/pal/unix/thread.rs:108:17
  48:     0x7042d18a955a - <unknown>
  49:     0x7042d1926a3c - <unknown>
  50:                0x0 - <unknown>

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 1.80.0-nightly (91d5e4af8 2024-04-28) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [param_env] computing normalized predicates of `<impl at /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:18:1: 22:18>`
#1 [check_well_formed] checking that `<impl at /tmp/icemaker_global_tempdir.o1fucsK3WfMn/rustc_testrunner_tmpdir_reporting.5gsYH20SuKQM/mvce.rs:18:1: 22:18>` is well-formed
#2 [check_mod_type_wf] checking that types are well-formed in top-level module
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 7 previous errors

Some errors have detailed explanations: E0207, E0403, E0412, E0425, E0601.
For more information about an error, try `rustc --explain E0207`.