thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src\librustc\hir\mod.rs:81:37
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
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 1.44.0-nightly (7ceebd98c 2020-03-17) running on x86_64-pc-windows-msvc
note: compiler flags: -C debuginfo=2 --crate-type lib
note: some of the compiler flags provided by cargo are hidden
error: could not compile `docopt`.
To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: build failed
Backtrace
```
$ cargo +nightly build
Compiling docopt v1.1.0
thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src\librustc\hir\mod.rs:81:37
stack backtrace:
0: ::fmt
1: core::fmt::write
2: ::fmt
3: std::panicking::take_hook
4: std::panicking::take_hook
5: rustc_driver::report_ice
6: std::panicking::rust_panic_with_hook
7: rust_begin_unwind
8: core::panicking::panic_fmt
9: core::panicking::panic
10: rustc::ty::structural_impls::::lift_to_tcx
11: rustc::ty::::is_object_safe
12: rustc::dep_graph::graph::DepGraph::assert_ignored
13: rustc::ty::query::plumbing::::try_print_query_stack
14: rustc::hir::map::Map::find_entry
15: rustc::hir::map::Map::find
16: ::visit_expr
17: ::visit_foreign_item
18: rustc_passes::dead::check_crate
19: rustc_interface::interface::parse_cfgspecs
20: rustc_interface::queries::Linker::link
21: rustc_interface::passes::QueryContext::print_stats
22: rustc_errors::snippet::MultilineAnnotation::increase_depth
23: as rustc_ast::attr::HasAttrs>::attrs
24: as rustc_ast::attr::HasAttrs>::attrs
25: ::fmt
26: as rustc_ast::attr::HasAttrs>::attrs
27: ::deref
28: as rustc_ast::attr::HasAttrs>::attrs
29: ZN244_$LT$std..error..$LT$impl$u20$core..convert..From$LT$alloc..string..String$GT$$u20$for$u20$alloc..boxed..Box$LT$dyn$u20$std..error.
.Error$u2b$core..marker..Send$u2b$core..marker..Sync$GT$$GT$..from..StringError$u20$as$u20$core..fmt..Display$GT$3fmt17
30: std::sys::windows::thread::Thread::new
31: BaseThreadInitThunk
32: RtlUserThreadStart
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
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 1.44.0-nightly (7ceebd98c 2020-03-17) running on x86_64-pc-windows-msvc
note: compiler flags: -C debuginfo=2 --crate-type lib
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
#0 [hir_owner] processing `regex`
#1 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `docopt`.
To learn more, run the command again with --verbose.
```
Code
Sorry to not provide something more precise, but this was reported to me by Travis here: https://travis-ci.com/github/ChrisGreenaway/cargo-local-registry/jobs/299634154
You can reproduce it with:
But it looks like the problem was caused by some code in the docopt crate.
Meta
rustc --version --verbose
:Error output
Backtrace
``` $ cargo +nightly build Compiling docopt v1.1.0 thread 'rustc' panicked at 'called `Option::unwrap()` on a `None` value', src\librustc\hir\mod.rs:81:37 stack backtrace: 0:::fmt
1: core::fmt::write
2: ::fmt
3: std::panicking::take_hook
4: std::panicking::take_hook
5: rustc_driver::report_ice
6: std::panicking::rust_panic_with_hook
7: rust_begin_unwind
8: core::panicking::panic_fmt
9: core::panicking::panic
10: rustc::ty::structural_impls::::lift_to_tcx
11: rustc::ty::::is_object_safe
12: rustc::dep_graph::graph::DepGraph::assert_ignored
13: rustc::ty::query::plumbing::::try_print_query_stack
14: rustc::hir::map::Map::find_entry
15: rustc::hir::map::Map::find
16: ::visit_expr
17: ::visit_foreign_item
18: rustc_passes::dead::check_crate
19: rustc_interface::interface::parse_cfgspecs
20: rustc_interface::queries::Linker::link
21: rustc_interface::passes::QueryContext::print_stats
22: rustc_errors::snippet::MultilineAnnotation::increase_depth
23: as rustc_ast::attr::HasAttrs>::attrs
24: as rustc_ast::attr::HasAttrs>::attrs
25: ::fmt
26: as rustc_ast::attr::HasAttrs>::attrs
27: ::deref
28: as rustc_ast::attr::HasAttrs>::attrs
29: ZN244_$LT$std..error..$LT$impl$u20$core..convert..From$LT$alloc..string..String$GT$$u20$for$u20$alloc..boxed..Box$LT$dyn$u20$std..error.
.Error$u2b$core..marker..Send$u2b$core..marker..Sync$GT$$GT$..from..StringError$u20$as$u20$core..fmt..Display$GT$3fmt17
30: std::sys::windows::thread::Thread::new
31: BaseThreadInitThunk
32: RtlUserThreadStart
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
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 1.44.0-nightly (7ceebd98c 2020-03-17) running on x86_64-pc-windows-msvc
note: compiler flags: -C debuginfo=2 --crate-type lib
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
#0 [hir_owner] processing `regex`
#1 [analysis] running analysis passes on this crate
end of query stack
error: could not compile `docopt`.
To learn more, run the command again with --verbose.
```