ICE: `no entry found for key` generics_of.rs

[matthiaskrgr]

Code

#![feature(generic_const_exprs)]

pub fn String<V>(elem)
where
    V: 'a,
    for<const N: usize = { || {}}> V: 'a, 
    for<C2: , R2, R3: > <&str as IntoIterator>::Item: 'static,
{}

Meta

rustc --version --verbose:

rustc 1.72.0-nightly (22e9fe644 2023-06-23)
binary: rustc
commit-hash: 22e9fe644ea710eec50cb0aabcae7fa8dd9fd675
commit-date: 2023-06-23
host: x86_64-unknown-linux-gnu
release: 1.72.0-nightly
LLVM version: 16.0.5

Error output

Backtrace

thread 'rustc' panicked at 'no entry found for key', compiler/rustc_hir_analysis/src/collect/generics_of.rs:88:41
stack backtrace:
   0:     0x7f2308367e31 - std::backtrace_rs::backtrace::libunwind::trace::h45c8b5b393354aaa
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x7f2308367e31 - std::backtrace_rs::backtrace::trace_unsynchronized::hc5cde6aeff03cc23
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f2308367e31 - std::sys_common::backtrace::_print_fmt::h86fd79bdeff6c899
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:65:5
   3:     0x7f2308367e31 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h0f1168665e8c8865
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:44:22
   4:     0x7f23083c95df - core::fmt::rt::Argument::fmt::hfed1a51422c978b7
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/fmt/rt.rs:138:9
   5:     0x7f23083c95df - core::fmt::write::h4dfc2a0c62cf3fd6
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/fmt/mod.rs:1094:21
   6:     0x7f230835a967 - std::io::Write::write_fmt::ha45cc30dd6a81686
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/io/mod.rs:1714:15
   7:     0x7f2308367c45 - std::sys_common::backtrace::_print::h14294ae8d055d04e
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:47:5
   8:     0x7f2308367c45 - std::sys_common::backtrace::print::hf007ea148056754d
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:34:9
   9:     0x7f230836a9f3 - std::panicking::default_hook::{{closure}}::h12f0e86c17019fae
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:269:22
  10:     0x7f230836a784 - std::panicking::default_hook::h3e363e70e8823128
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:288:9
  11:     0x7f230b603eab - rustc_driver_impl[1ee18bc64acaad37]::install_ice_hook::{closure#0}
  12:     0x7f230836b21e - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h6345ba7ef09e0a3b
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/alloc/src/boxed.rs:2007:9
  13:     0x7f230836b21e - std::panicking::rust_panic_with_hook::he3112cb9ec41f5a5
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:709:13
  14:     0x7f230836afa7 - std::panicking::begin_panic_handler::{{closure}}::ha789ef310202fe47
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:597:13
  15:     0x7f2308368266 - std::sys_common::backtrace::__rust_end_short_backtrace::h455eb16e2038ff87
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys_common/backtrace.rs:151:18
  16:     0x7f230836acf2 - rust_begin_unwind
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/panicking.rs:593:5
  17:     0x7f23083c5833 - core::panicking::panic_fmt::h911f0f6c6f3e2e92
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/panicking.rs:67:14
  18:     0x7f23083c5593 - core::panicking::panic_display::h474868786ec72e4f
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/panicking.rs:150:5
  19:     0x7f23083c5593 - core::panicking::panic_str::h44f3789074067b1e
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/panicking.rs:134:5
  20:     0x7f23083c5593 - core::option::expect_failed::h3a7a4c408a01161b
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/core/src/option.rs:1952:5
  21:     0x7f2309efe68c - rustc_hir_analysis[bed39c5e84d3e350]::collect::generics_of::generics_of
  22:     0x7f2309efa998 - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[30672f8f3d90a755]::query_impl::generics_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 8usize]>>
  23:     0x7f2309efa930 - <rustc_query_impl[30672f8f3d90a755]::query_impl::generics_of::dynamic_query::{closure#2} as core[db7c5f9f8e26b951]::ops::function::FnOnce<(rustc_middle[aeb3147772634dcd]::ty::context::TyCtxt, rustc_span[8155bebf48a1eb91]::def_id::DefId)>>::call_once
  24:     0x7f230963d515 - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::<rustc_query_impl[30672f8f3d90a755]::DynamicConfig<rustc_query_system[29d9bde875297da0]::query::caches::DefaultCache<rustc_span[8155bebf48a1eb91]::def_id::DefId, rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false>
  25:     0x7f230af6e963 - rustc_query_impl[30672f8f3d90a755]::query_impl::generics_of::get_query_non_incr::__rust_end_short_backtrace
  26:     0x7f2309efc2fd - rustc_hir_analysis[bed39c5e84d3e350]::collect::generics_of::generics_of
  27:     0x7f2309efa998 - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[30672f8f3d90a755]::query_impl::generics_of::dynamic_query::{closure#2}::{closure#0}, rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 8usize]>>
  28:     0x7f2309efa930 - <rustc_query_impl[30672f8f3d90a755]::query_impl::generics_of::dynamic_query::{closure#2} as core[db7c5f9f8e26b951]::ops::function::FnOnce<(rustc_middle[aeb3147772634dcd]::ty::context::TyCtxt, rustc_span[8155bebf48a1eb91]::def_id::DefId)>>::call_once
  29:     0x7f230963d515 - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::<rustc_query_impl[30672f8f3d90a755]::DynamicConfig<rustc_query_system[29d9bde875297da0]::query::caches::DefaultCache<rustc_span[8155bebf48a1eb91]::def_id::DefId, rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false>
  30:     0x7f230af6e963 - rustc_query_impl[30672f8f3d90a755]::query_impl::generics_of::get_query_non_incr::__rust_end_short_backtrace
  31:     0x7f230967380b - <rustc_hir_analysis[bed39c5e84d3e350]::collect::CollectItemTypesVisitor as rustc_hir[f5b2dc8658a8d394]::intravisit::Visitor>::visit_expr
  32:     0x7f2309673676 - <rustc_hir_analysis[bed39c5e84d3e350]::collect::CollectItemTypesVisitor as rustc_hir[f5b2dc8658a8d394]::intravisit::Visitor>::visit_expr
  33:     0x7f230979d0e9 - <rustc_hir_analysis[bed39c5e84d3e350]::collect::CollectItemTypesVisitor as rustc_hir[f5b2dc8658a8d394]::intravisit::Visitor>::visit_generics
  34:     0x7f2309ed26eb - rustc_hir[f5b2dc8658a8d394]::intravisit::walk_item::<rustc_hir_analysis[bed39c5e84d3e350]::collect::CollectItemTypesVisitor>
  35:     0x7f2309ed03dd - <rustc_hir_analysis[bed39c5e84d3e350]::collect::CollectItemTypesVisitor as rustc_hir[f5b2dc8658a8d394]::intravisit::Visitor>::visit_item
  36:     0x7f2309eccc43 - rustc_hir_analysis[bed39c5e84d3e350]::collect::collect_mod_item_types
  37:     0x7f230a2d6aec - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[30672f8f3d90a755]::query_impl::collect_mod_item_types::dynamic_query::{closure#2}::{closure#0}, rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 0usize]>>
  38:     0x7f230a2d6ace - <rustc_query_impl[30672f8f3d90a755]::query_impl::collect_mod_item_types::dynamic_query::{closure#2} as core[db7c5f9f8e26b951]::ops::function::FnOnce<(rustc_middle[aeb3147772634dcd]::ty::context::TyCtxt, rustc_span[8155bebf48a1eb91]::def_id::LocalDefId)>>::call_once
  39:     0x7f2309cf518f - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::<rustc_query_impl[30672f8f3d90a755]::DynamicConfig<rustc_query_system[29d9bde875297da0]::query::caches::VecCache<rustc_span[8155bebf48a1eb91]::def_id::LocalDefId, rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false>
  40:     0x7f230af7fd14 - rustc_query_impl[30672f8f3d90a755]::query_impl::collect_mod_item_types::get_query_non_incr::__rust_end_short_backtrace
  41:     0x7f230aa98b77 - <rustc_middle[aeb3147772634dcd]::hir::map::Map>::for_each_module::<rustc_hir_analysis[bed39c5e84d3e350]::check_crate::{closure#0}::{closure#0}::{closure#0}>
  42:     0x7f230aa98752 - <rustc_session[91ea302e4bbb4392]::session::Session>::track_errors::<rustc_hir_analysis[bed39c5e84d3e350]::check_crate::{closure#0}, ()>
  43:     0x7f230aa96f51 - rustc_hir_analysis[bed39c5e84d3e350]::check_crate
  44:     0x7f230aa8fb6a - rustc_interface[3e44238a9783f3c8]::passes::analysis
  45:     0x7f230aadc83a - rustc_query_impl[30672f8f3d90a755]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[30672f8f3d90a755]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 1usize]>>
  46:     0x7f230aadc829 - <rustc_query_impl[30672f8f3d90a755]::query_impl::analysis::dynamic_query::{closure#2} as core[db7c5f9f8e26b951]::ops::function::FnOnce<(rustc_middle[aeb3147772634dcd]::ty::context::TyCtxt, ())>>::call_once
  47:     0x7f230ac71c18 - rustc_query_system[29d9bde875297da0]::query::plumbing::try_execute_query::<rustc_query_impl[30672f8f3d90a755]::DynamicConfig<rustc_query_system[29d9bde875297da0]::query::caches::SingleCache<rustc_middle[aeb3147772634dcd]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[30672f8f3d90a755]::plumbing::QueryCtxt, false>
  48:     0x7f230ac719e9 - rustc_query_impl[30672f8f3d90a755]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  49:     0x7f230ac28485 - <rustc_middle[aeb3147772634dcd]::ty::context::GlobalCtxt>::enter::<rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}::{closure#2}::{closure#4}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>
  50:     0x7f230a803f4b - <rustc_interface[3e44238a9783f3c8]::interface::Compiler>::enter::<rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}::{closure#2}, core[db7c5f9f8e26b951]::result::Result<core[db7c5f9f8e26b951]::option::Option<rustc_interface[3e44238a9783f3c8]::queries::Linker>, rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>
  51:     0x7f230a7ffd99 - rustc_span[8155bebf48a1eb91]::set_source_map::<core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>, rustc_interface[3e44238a9783f3c8]::interface::run_compiler<core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}::{closure#0}>
  52:     0x7f230a7ff8c5 - <scoped_tls[5f3106920672553]::ScopedKey<rustc_span[8155bebf48a1eb91]::SessionGlobals>>::set::<rustc_interface[3e44238a9783f3c8]::interface::run_compiler<core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>
  53:     0x7f230a7feee6 - std[590ba7ead67831d4]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[3e44238a9783f3c8]::util::run_in_thread_pool_with_globals<rustc_interface[3e44238a9783f3c8]::interface::run_compiler<core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>
  54:     0x7f230ae73945 - <<std[590ba7ead67831d4]::thread::Builder>::spawn_unchecked_<rustc_interface[3e44238a9783f3c8]::util::run_in_thread_pool_with_globals<rustc_interface[3e44238a9783f3c8]::interface::run_compiler<core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>, rustc_driver_impl[1ee18bc64acaad37]::run_compiler::{closure#1}>::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[db7c5f9f8e26b951]::result::Result<(), rustc_span[8155bebf48a1eb91]::ErrorGuaranteed>>::{closure#1} as core[db7c5f9f8e26b951]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  55:     0x7f2308375695 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h2e6f8aee19cb9bca
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/alloc/src/boxed.rs:1993:9
  56:     0x7f2308375695 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h4548c5cdbeb5a136
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/alloc/src/boxed.rs:1993:9
  57:     0x7f2308375695 - std::sys::unix::thread::Thread::new::thread_start::h57734a91bfb8a041
                               at /rustc/22e9fe644ea710eec50cb0aabcae7fa8dd9fd675/library/std/src/sys/unix/thread.rs:108:17
  58:     0x7f230810d44b - <unknown>
  59:     0x7f2308190e40 - <unknown>
  60:                0x0 - <unknown>

error: the compiler unexpectedly panicked. this is a bug.

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 1.72.0-nightly (22e9fe644 2023-06-23) running on x86_64-unknown-linux-gnu

query stack during panic:
#0 [generics_of] computing generics of `String::{constant#0}`
#1 [generics_of] computing generics of `String::{constant#0}::{closure#0}`
#2 [collect_mod_item_types] collecting item types in top-level module
#3 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to 7 previous errors; 1 warning emitted

Some errors have detailed explanations: E0261, E0601, E0637, E0658.
For more information about an error, try `rustc --explain E0261`.

[matthiaskrgr]

Crashes since at least stable rustc 1.60.0.
Wish we could prevent unstable features from leaking ices into the stable line somehow :/

[workingjubilee]

It would be very easy to do that if rustc decided to stop providing the quality of diagnostics that it does, and e.g. simply collected all parse errors and printed them for the user. Instead, it looks at utterly nonsensical input and tries to keep going so it can offer help.

[BoxyUwU]

pub fn foo()
where
    for<const N: usize = { || {}; 1 }> ():, 
{}

seems to be a more minimal repro (although its hard to tell from just the backtraces whether its the same underlying cause) If you add feature(generic_const_exprs) its the same ICE as in the issue descr

[asquared31415]

That appears to be a different ICE message on stable 1.70.0 than when the feature is enabled, not sure if that is relevant here.

[workingjubilee]

It ices in the same point of the code, generics_of.rs:88:41, given

#![feature(generic_const_exprs)]
pub fn foo()
where
    for<const N: usize = { || {}; 1 }> ():, 
{}

EDIT: cat!

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-medium