Closed
Description
playground
ICE when some lints fail on an async-fn. Make the xs mutable and no ICE.
#![feature(async_await)]
// x should be mutable
pub async fn f(x: Option<usize>) {
x.take();
}
// without the above failure, this fails as expected
pub async fn g(x: usize) {
x += 1;
} Compiling playground v0.0.1 (/playground)
warning: variable `a` is assigned to, but never used
--> src/lib.rs:8:16
|
8 | pub async fn g(a: usize) {
| ^
|
= note: #[warn(unused_variables)] on by default
= note: consider using `_a` instead
warning: value assigned to `a` is never read
--> src/lib.rs:9:5
|
9 | a += 1;
| ^
|
= note: #[warn(unused_assignments)] on by default
= help: maybe it is overwritten before being read?
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:347:21
stack backtrace:
0: backtrace::backtrace::libunwind::trace
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.25/src/backtrace/libunwind.rs:97
1: backtrace::backtrace::trace_unsynchronized
at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.25/src/backtrace/mod.rs:66
2: std::sys_common::backtrace::_print
at src/libstd/sys_common/backtrace.rs:47
3: std::sys_common::backtrace::print
at src/libstd/sys_common/backtrace.rs:36
4: std::panicking::default_hook::{{closure}}
at src/libstd/panicking.rs:197
5: std::panicking::default_hook
at src/libstd/panicking.rs:211
6: rustc::util::common::panic_hook
7: std::panicking::rust_panic_with_hook
at src/libstd/panicking.rs:478
8: std::panicking::continue_panic_fmt
at src/libstd/panicking.rs:381
9: rust_begin_unwind
at src/libstd/panicking.rs:308
10: core::panicking::panic_fmt
at src/libcore/panicking.rs:85
11: core::panicking::panic
at src/libcore/panicking.rs:49
12: rustc_mir::borrow_check::mutability_errors::<impl rustc_mir::borrow_check::MirBorrowckCtxt>::report_mutability_error
13: rustc_mir::borrow_check::MirBorrowckCtxt::access_place
14: <rustc_mir::borrow_check::MirBorrowckCtxt as rustc_mir::dataflow::DataflowResultsConsumer>::visit_statement_entry
15: rustc_mir::borrow_check::do_mir_borrowck
16: rustc::ty::context::GlobalCtxt::enter_local
17: rustc_mir::borrow_check::mir_borrowck
18: rustc::ty::query::__query_compute::mir_borrowck
19: rustc::ty::query::<impl rustc::ty::query::config::QueryAccessors for rustc::ty::query::queries::mir_borrowck>::compute
20: rustc::dep_graph::graph::DepGraph::with_task_impl
21: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
22: rustc::ty::<impl rustc::ty::context::TyCtxt>::par_body_owners
23: rustc::util::common::time
24: rustc_interface::passes::analysis
25: rustc::ty::query::__query_compute::analysis
26: rustc::dep_graph::graph::DepGraph::with_task_impl
27: rustc::ty::query::plumbing::<impl rustc::ty::context::TyCtxt>::get_query
28: rustc::ty::context::tls::enter_global
29: rustc_interface::passes::BoxedGlobalCtxt::access::{{closure}}
30: rustc_interface::passes::create_global_ctxt::{{closure}}
31: rustc_interface::interface::run_compiler_in_existing_thread_pool
32: std::thread::local::LocalKey<T>::with
33: scoped_tls::ScopedKey<T>::set
34: syntax::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
query stack during panic:
#0 [mir_borrowck] processing `f::{{closure}}#0`
#1 [analysis] running analysis passes on this crate
end of query stack
error: internal compiler error: unexpected panic
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 1.37.0-nightly (03ee55bb1 2019-06-01) running on x86_64-unknown-linux-gnu
note: compiler flags: -C codegen-units=1 -C debuginfo=2 --crate-type lib
note: some of the compiler flags provided by cargo are hidden
error: Could not compile `playground`.
To learn more, run the command again with --verbose.