ICE: `generic_const_exprs`: `unexpected non-type Node::GenericParam`,

[matthiaskrgr]

Code

#![crate_type = "lib"]
#![feature(generic_const_exprs)]
trait B {
    type U<T: A>;
}

fn f<T: B<U<1i32> = ()>>() {}

Meta

rustc --version --verbose:

rustc 1.70.0-nightly (13afbdaa0 2023-03-17)
binary: rustc
commit-hash: 13afbdaa0655dda23d7129e59ac48f1ec88b2084
commit-date: 2023-03-17
host: x86_64-unknown-linux-gnu
release: 1.70.0-nightly
LLVM version: 15.0.7

Error output

error[E0405]: cannot find trait `A` in this scope
 --> treereduce.out:4:15
  |
4 |     type U<T: A>;
  |               ^ not found in this scope

warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
 --> <crate attribute>:1:9
  |
1 | feature(generic_const_exprs)
  |         ^^^^^^^^^^^^^^^^^^^
  |
  = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
  = note: `#[warn(incomplete_features)]` on by default

error[E0601]: `main` function not found in crate `treereduce`
 --> treereduce.out:7:30
  |
7 | fn f<T: B<U<1i32> = ()>>() {}
  |                              ^ consider adding a `main` function to `treereduce.out`

warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
 --> treereduce.out:1:1
  |
1 | #[crate_type = "lib"]
  | ^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_attributes)]` on by default

error[E0747]: constant provided when a type was expected
 --> treereduce.out:7:13
  |
7 | fn f<T: B<U<1i32> = ()>>() {}
  |             ^^^^

Backtrace

error: internal compiler error: compiler/rustc_hir_analysis/src/collect/type_of.rs:549:18: unexpected non-type Node::GenericParam: Type { default: None, synthetic: false }

thread 'rustc' panicked at 'Box<dyn Any>', /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/compiler/rustc_errors/src/lib.rs:1644:9
stack backtrace:
   0:     0x7fb10336739a - std::backtrace_rs::backtrace::libunwind::trace::h84d2711f38e4d049
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7fb10336739a - std::backtrace_rs::backtrace::trace_unsynchronized::h07f6ebc5344709db
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7fb10336739a - std::sys_common::backtrace::_print_fmt::h05a29271ab24b307
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7fb10336739a - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h2badcaa62266c6d2
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7fb1033ca9be - core::fmt::write::h029bd029dcf67de1
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/core/src/fmt/mod.rs:1254:17
   5:     0x7fb10335a225 - std::io::Write::write_fmt::h80e1934b9bd451b8
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/io/mod.rs:1684:15
   6:     0x7fb103367165 - std::sys_common::backtrace::_print::hd15e10f9274c89b0
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:47:5
   7:     0x7fb103367165 - std::sys_common::backtrace::print::h170965e4e66b5ee4
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys_common/backtrace.rs:34:9
   8:     0x7fb103369edf - std::panicking::default_hook::{{closure}}::h0164004bb09e0366
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/panicking.rs:271:22
   9:     0x7fb103369c1b - std::panicking::default_hook::h5e2940911ec5582f
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/panicking.rs:290:9
  10:     0x7fb1065f2415 - rustc_driver_impl[bad2ed848d64dbdc]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7fb10336a71d - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h0f3cc38fa49d6ba4
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/alloc/src/boxed.rs:2002:9
  12:     0x7fb10336a71d - std::panicking::rust_panic_with_hook::h591d1df500c4db69
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/panicking.rs:696:13
  13:     0x7fb106b2aef1 - std[b4247acdb72724ff]::panicking::begin_panic::<rustc_errors[48bb1377a0478866]::ExplicitBug>::{closure#0}
  14:     0x7fb106b28996 - std[b4247acdb72724ff]::sys_common::backtrace::__rust_end_short_backtrace::<std[b4247acdb72724ff]::panicking::begin_panic<rustc_errors[48bb1377a0478866]::ExplicitBug>::{closure#0}, !>
  15:     0x7fb106b3ec96 - std[b4247acdb72724ff]::panicking::begin_panic::<rustc_errors[48bb1377a0478866]::ExplicitBug>
  16:     0x7fb106ba10d6 - std[b4247acdb72724ff]::panic::panic_any::<rustc_errors[48bb1377a0478866]::ExplicitBug>
  17:     0x7fb106b9e896 - <rustc_errors[48bb1377a0478866]::HandlerInner>::bug::<&alloc[c5857ad37805d36e]::string::String>
  18:     0x7fb106b9e560 - <rustc_errors[48bb1377a0478866]::Handler>::bug::<&alloc[c5857ad37805d36e]::string::String>
  19:     0x7fb106b9684b - rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt::<rustc_span[4d522547309d7b79]::span_encoding::Span>::{closure#0}
  20:     0x7fb106b9529a - rustc_middle[eaf6378de1cdbfa8]::ty::context::tls::with_opt::<rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt<rustc_span[4d522547309d7b79]::span_encoding::Span>::{closure#0}, !>::{closure#0}
  21:     0x7fb106b95266 - rustc_middle[eaf6378de1cdbfa8]::ty::context::tls::with_context_opt::<rustc_middle[eaf6378de1cdbfa8]::ty::context::tls::with_opt<rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt<rustc_span[4d522547309d7b79]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
  22:     0x7fb106b96796 - rustc_middle[eaf6378de1cdbfa8]::util::bug::opt_span_bug_fmt::<rustc_span[4d522547309d7b79]::span_encoding::Span>
  23:     0x7fb104c874e3 - rustc_middle[eaf6378de1cdbfa8]::util::bug::bug_fmt
  24:     0x7fb105d03ac5 - rustc_hir_analysis[7035f0189d3c093a]::collect::type_of::type_of
  25:     0x7fb104edebad - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::type_of, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  26:     0x7fb104edd7bd - <rustc_query_impl[1cc93b35ef872c79]::Queries as rustc_middle[eaf6378de1cdbfa8]::ty::query::QueryEngine>::type_of
  27:     0x7fb105d05113 - rustc_hir_analysis[7035f0189d3c093a]::collect::type_of::type_of
  28:     0x7fb104edebad - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::type_of, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  29:     0x7fb104edd7bd - <rustc_query_impl[1cc93b35ef872c79]::Queries as rustc_middle[eaf6378de1cdbfa8]::ty::query::QueryEngine>::type_of
  30:     0x7fb1057e4476 - <rustc_middle[eaf6378de1cdbfa8]::ty::consts::Const>::from_opt_const_arg_anon_const
  31:     0x7fb10677b49e - <rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::const_evaluatable_predicates_of::ConstCollector as rustc_hir[f188a593009d666f]::intravisit::Visitor>::visit_anon_const
  32:     0x7fb1067439fa - rustc_hir[f188a593009d666f]::intravisit::walk_generic_args::<rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::const_evaluatable_predicates_of::ConstCollector>
  33:     0x7fb106744d44 - rustc_hir[f188a593009d666f]::intravisit::walk_assoc_type_binding::<rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::const_evaluatable_predicates_of::ConstCollector>
  34:     0x7fb106743a20 - rustc_hir[f188a593009d666f]::intravisit::walk_generic_args::<rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::const_evaluatable_predicates_of::ConstCollector>
  35:     0x7fb106747c0d - rustc_hir[f188a593009d666f]::intravisit::walk_path::<rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::const_evaluatable_predicates_of::ConstCollector>
  36:     0x7fb1067449f0 - rustc_hir[f188a593009d666f]::intravisit::walk_where_predicate::<rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::const_evaluatable_predicates_of::ConstCollector>
  37:     0x7fb1067424e4 - rustc_hir[f188a593009d666f]::intravisit::walk_generics::<rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::const_evaluatable_predicates_of::ConstCollector>
  38:     0x7fb104c121c5 - rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_of::gather_explicit_predicates_of
  39:     0x7fb104c09c5f - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::explicit_predicates_of, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  40:     0x7fb104cc9633 - rustc_hir_analysis[7035f0189d3c093a]::collect::predicates_defined_on
  41:     0x7fb104cc7abc - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::predicates_defined_on, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  42:     0x7fb104fdfaed - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::predicates_of, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  43:     0x7fb104fdea4f - <rustc_query_impl[1cc93b35ef872c79]::Queries as rustc_middle[eaf6378de1cdbfa8]::ty::query::QueryEngine>::predicates_of
  44:     0x7fb104d56d84 - <rustc_hir_analysis[7035f0189d3c093a]::collect::CollectItemTypesVisitor as rustc_hir[f188a593009d666f]::intravisit::Visitor>::visit_item
  45:     0x7fb104d55895 - <rustc_middle[eaf6378de1cdbfa8]::hir::map::Map>::visit_item_likes_in_module::<rustc_hir_analysis[7035f0189d3c093a]::collect::CollectItemTypesVisitor>
  46:     0x7fb104d557ac - rustc_hir_analysis[7035f0189d3c093a]::collect::collect_mod_item_types
  47:     0x7fb105c561c5 - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::collect_mod_item_types, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  48:     0x7fb105c55dc3 - <rustc_query_impl[1cc93b35ef872c79]::Queries as rustc_middle[eaf6378de1cdbfa8]::ty::query::QueryEngine>::collect_mod_item_types
  49:     0x7fb104952f63 - <rustc_session[8656a7a78cf578e4]::session::Session>::track_errors::<rustc_hir_analysis[7035f0189d3c093a]::check_crate::{closure#0}, ()>
  50:     0x7fb10494f832 - rustc_hir_analysis[7035f0189d3c093a]::check_crate
  51:     0x7fb104946742 - rustc_interface[dde792dfc5bb5edd]::passes::analysis
  52:     0x7fb105e11aec - rustc_query_system[3b264ab6e948b942]::query::plumbing::try_execute_query::<rustc_query_impl[1cc93b35ef872c79]::queries::analysis, rustc_query_impl[1cc93b35ef872c79]::plumbing::QueryCtxt>
  53:     0x7fb105e117e0 - <rustc_query_impl[1cc93b35ef872c79]::Queries as rustc_middle[eaf6378de1cdbfa8]::ty::query::QueryEngine>::analysis
  54:     0x7fb105c6e109 - <rustc_middle[eaf6378de1cdbfa8]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>
  55:     0x7fb1057f852d - <rustc_interface[dde792dfc5bb5edd]::interface::Compiler>::enter::<rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}::{closure#2}, core[9847d4a2e8a02df2]::result::Result<core[9847d4a2e8a02df2]::option::Option<rustc_interface[dde792dfc5bb5edd]::queries::Linker>, rustc_span[4d522547309d7b79]::ErrorGuaranteed>>
  56:     0x7fb1057f6630 - rustc_span[4d522547309d7b79]::with_source_map::<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_interface[dde792dfc5bb5edd]::interface::run_compiler<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  57:     0x7fb1057f5bd9 - std[b4247acdb72724ff]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[dde792dfc5bb5edd]::util::run_in_thread_pool_with_globals<rustc_interface[dde792dfc5bb5edd]::interface::run_compiler<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}>::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>
  58:     0x7fb105ee6afa - <<std[b4247acdb72724ff]::thread::Builder>::spawn_unchecked_<rustc_interface[dde792dfc5bb5edd]::util::run_in_thread_pool_with_globals<rustc_interface[dde792dfc5bb5edd]::interface::run_compiler<core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>, rustc_driver_impl[bad2ed848d64dbdc]::run_compiler::{closure#1}>::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[9847d4a2e8a02df2]::result::Result<(), rustc_span[4d522547309d7b79]::ErrorGuaranteed>>::{closure#1} as core[9847d4a2e8a02df2]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  59:     0x7fb1033745f3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h51bca2043facf7d3
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/alloc/src/boxed.rs:1988:9
  60:     0x7fb1033745f3 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h365da710d54db7ab
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/alloc/src/boxed.rs:1988:9
  61:     0x7fb1033745f3 - std::sys::unix::thread::Thread::new::thread_start::hb322f3a535acf0fe
                               at /rustc/13afbdaa0655dda23d7129e59ac48f1ec88b2084/library/std/src/sys/unix/thread.rs:108:17
  62:     0x7fb103106bb5 - <unknown>
  63:     0x7fb103188d90 - <unknown>
  64:                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 1.70.0-nightly (13afbdaa0 2023-03-17) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z crate-attr=feature(generic_const_exprs)

query stack during panic:
#0 [type_of] computing type of `B::U::T`
#1 [type_of] computing type of `f::{constant#0}`
#2 [explicit_predicates_of] computing explicit predicates of `f`
#3 [predicates_defined_on] computing predicates of `f`
#4 [predicates_of] computing predicates of `f`
#5 [collect_mod_item_types] collecting item types in top-level module
#6 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 4 previous errors; 2 warnings emitted

Some errors have detailed explanations: E0405, E0601, E0747.
For more information about an error, try `rustc --explain E0405`.

[matthiaskrgr]

searched nightlies: from nightly-2022-12-30 to nightly-2023-03-18
regressed nightly: nightly-2023-01-01
searched commit range: ce85c98...574b64a
regressed commit: 247e44e

bisected with cargo-bisect-rustc v0.6.5

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

cargo bisect-rustc --script=/home/matthias/vcs/github/rust_bisect/script.sh --test-dir=/home/matthias/vcs/github/rust_bisect/foo

Regression in rust-lang-ci@e3e79ed

[matthiaskrgr]

aaah shit, the commit only modified the backtrace 😆 so "panicked at" no longer triggers before that..

[matthiaskrgr]

********************************************************************************
Regression in nightly-2022-09-30
********************************************************************************

fetching https://static.rust-lang.org/dist/2022-09-29/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2022-09-29: 40 B / 40 B [============================================================================================] 100.00 % 514.57 KB/s converted 2022-09-29 to ce7f0f1aa0f02c45cad0749e63f3086234b1f422
fetching https://static.rust-lang.org/dist/2022-09-30/channel-rust-nightly-git-commit-hash.txt
nightly manifest 2022-09-30: 40 B / 40 B [==============================================================================================] 100.00 % 1.09 MB/s converted 2022-09-30 to 9c56d9d6fec6262bbb1549cfe466a812ae2c6523
looking for regression commit between 2022-09-29 and 2022-09-30
opening existing repository at "rust.git"
Found origin remote under name `origin`
refreshing repository at "rust.git"
fetching (via local git) commits from ce7f0f1aa0f02c45cad0749e63f3086234b1f422 to 9c56d9d6fec6262bbb1549cfe466a812ae2c6523
opening existing repository at "rust.git"
Found origin remote under name `origin`
refreshing repository at "rust.git"
looking up first commit
looking up second commit
checking that commits are by bors and thus have ci artifacts...
finding bors merge commits
found 9 bors merge commits in the specified range
  commit[0] 2022-09-28UTC: Auto merge of #100719 - CohenArthur:rust-safe-intrinsic-attribute, r=wesleywiser
  commit[1] 2022-09-28UTC: Auto merge of #102384 - camelid:extrainfo, r=GuillaumeGomez
  commit[2] 2022-09-29UTC: Auto merge of #101833 - jyn514:cross-compile-compiler-builtins, r=Mark-Simulacrum
  commit[3] 2022-09-29UTC: Auto merge of #102450 - JohnTitor:rollup-ahleg93, r=JohnTitor
  commit[4] 2022-09-29UTC: Auto merge of #102328 - cuviper:ibm-stack-probes, r=nagisa
  commit[5] 2022-09-29UTC: Auto merge of #102461 - oli-obk:split_collect_rs, r=lcnr
  commit[6] 2022-09-29UTC: Auto merge of #102471 - Dylan-DPC:rollup-ij3okjt, r=Dylan-DPC
  commit[7] 2022-09-29UTC: Auto merge of #101893 - oli-obk:lift_derive, r=lcnr
  commit[8] 2022-09-29UTC: Auto merge of #102482 - notriddle:rollup-fjm618g, r=notriddle
ERROR: no CI builds available between ce7f0f1aa0f02c45cad0749e63f3086234b1f422 and 9c56d9d6fec6262bbb1549cfe466a812ae2c6523 within last 167 days

[BoxyUwU]

maybe #102336 @compiler-errors