Closed
Description
Hello !
A blank rust project with just this main.rs:
#![feature(const_generics)]
trait Trait {}
fn f<const N: usize>(_: impl Trait) {}
fn main() {}causes:
$ rustc --version
rustc 1.36.0-nightly (963184bbb 2019-05-18)
$ RUST_BACKTRACE=1 cargo check
Checking test-rust v0.1.0 (/home/carado/tmp/test-rust)
warning: the feature `const_generics` is incomplete and may cause the compiler to crash
--> src/main.rs:1:12
|
1 | #![feature(const_generics)]
| ^^^^^^^^^^^^^^
error: internal compiler error: src/librustc/ty/subst.rs:555: expected type for `impl Trait/#0` (impl Trait/0) but found Const(Const { ty: [type error], val: Scalar(Bits { size: 0, bits: 0 }) }) when substituting (root type=Some(impl Trait)) substs=[Const { ty: [type error], val: Scalar(Bits { size: 0, bits: 0 }) }, [type error]]
thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:572:9
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
at src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:39
1: std::sys_common::backtrace::_print
at src/libstd/sys_common/backtrace.rs:71
2: std::panicking::default_hook::{{closure}}
at src/libstd/sys_common/backtrace.rs:59
at src/libstd/panicking.rs:197
3: std::panicking::default_hook
at src/libstd/panicking.rs:211
4: rustc::util::common::panic_hook
5: std::panicking::rust_panic_with_hook
at src/libstd/panicking.rs:478
6: std::panicking::begin_panic
7: rustc_errors::Handler::span_bug
8: rustc::util::bug::opt_span_bug_fmt::{{closure}}
9: rustc::ty::context::tls::with_opt::{{closure}}
10: rustc::ty::context::tls::with_context_opt
11: rustc::ty::context::tls::with_opt
12: rustc::util::bug::opt_span_bug_fmt
13: rustc::util::bug::span_bug_fmt
14: <rustc::ty::subst::SubstFolder as rustc::ty::fold::TypeFolder>::fold_ty
15: rustc::ty::fold::TypeFoldable::fold_with
16: <smallvec::SmallVec<A> as core::iter::traits::collect::FromIterator<<A as smallvec::Array>::Item>>::from_iter
17: rustc::ty::fold::TypeFoldable::fold_with
18: rustc::ty::subst::Subst::subst
19: <core::iter::adapters::Map<I,F> as core::iter::traits::iterator::Iterator>::next
20: rustc_typeck::check::wfcheck::check_where_clauses
21: rustc_typeck::check::wfcheck::check_fn_or_method
22: rustc::ty::context::GlobalCtxt::enter_local
23: rustc_typeck::check::wfcheck::check_item_well_formed
24: rustc::ty::query::__query_compute::check_item_well_formed
25: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::check_item_well_formed>::compute
26: rustc::dep_graph::graph::DepGraph::with_task_impl
27: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
28: <rustc_typeck::check::wfcheck::CheckTypeWellFormedVisitor as rustc::hir::itemlikevisit::ParItemLikeVisitor>::visit_item
29: __rust_maybe_catch_panic
at src/libpanic_unwind/lib.rs:85
30: rustc_data_structures::sync::par_for_each_in
31: __rust_maybe_catch_panic
at src/libpanic_unwind/lib.rs:85
32: rustc::hir::Crate::par_visit_all_item_likes
33: rustc::util::common::time
34: rustc_typeck::check_crate
35: rustc_interface::passes::analysis
36: rustc::ty::query::__query_compute::analysis
37: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::analysis>::compute
38: rustc::dep_graph::graph::DepGraph::with_task_impl
39: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
40: rustc::ty::context::tls::enter_global
41: rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}}
42: rustc_interface::passes::create_global_ctxt::{{closure}}
43: rustc_interface::interface::run_compiler_in_existing_thread_pool
44: std::thread::local::LocalKey<T>::with
45: scoped_tls::ScopedKey<T>::set
46: syntax::with_globals
query stack during panic:
#0 [check_item_well_formed] processing `f`
#1 [analysis] running analysis passes on this crate
end of query stack
error: aborting due to previous error
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.36.0-nightly (963184bbb 2019-05-18) running on x86_64-unknown-linux-gnu
note: compiler flags: -C debuginfo=2 -C incremental --crate-type bin
note: some of the compiler flags provided by cargo are hidden
error: Could not compile `test-rust`.
To learn more, run the command again with --verbose.
And while I'm here, thanks in general for implementing const generics ! They're gonna be a huge help.
Have a nice day !