BacktraceStatus is borked

[dtolnay]

fn main() {
    let _ = std::backtrace::BacktraceStatus::Captured;
}

As of current nightly rustc 1.65.0-nightly (29e4a9e 2022-08-10):

warning: Error finalizing incremental compilation session directory `/git/repro/target/debug/incremental/repro-23roub2a2ui7m/s-gchtf270bu-9k52gi-working`: No such file or directory (os error 2)

error: internal compiler error: no errors encountered even though `delay_span_bug` issued

error: internal compiler error: encountered unmarked API: DefId(1:10648 ~ std[0cb1]::backtrace::BacktraceStatus::Captured::{constructor#0})
 --> src/main.rs:2:13
  |
2 |     let _ = std::backtrace::BacktraceStatus::Captured;
  |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: delayed at compiler/rustc_middle/src/middle/stability.rs:603:27

thread 'rustc' panicked at 'Box<dyn Any>', compiler/rustc_errors/src/lib.rs:1425:13
stack backtrace:
   0:     0x7f9cbef657e0 - std::backtrace_rs::backtrace::libunwind::trace::hea82fac2aae29b23
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   1:     0x7f9cbef657e0 - std::backtrace_rs::backtrace::trace_unsynchronized::h5517a70ae29c4a37
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f9cbef657e0 - std::sys_common::backtrace::_print_fmt::h15ae471bcdd82d93
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7f9cbef657e0 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h7e2315bde9966038
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7f9cbefc0cfc - core::fmt::write::h6c731326a8a30a57
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/core/src/fmt/mod.rs:1198:17
   5:     0x7f9cbef56935 - std::io::Write::write_fmt::h71584a2dd6c3063c
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/io/mod.rs:1672:15
   6:     0x7f9cbef684b1 - std::sys_common::backtrace::_print::h24f1c9f87e80a8e0
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7f9cbef684b1 - std::sys_common::backtrace::print::hf0c5754f46015782
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7f9cbef684b1 - std::panicking::default_hook::{{closure}}::h92f4071e73011988
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/panicking.rs:295:22
   9:     0x7f9cbef68183 - std::panicking::default_hook::h97b116f9b96b6bfa
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/panicking.rs:314:9
  10:     0x7f9cc17ea414 - rustc_driver[788d642ecae1365]::DEFAULT_HOOK::{closure#0}::{closure#0}
  11:     0x7f9cbef68ce6 - std::panicking::rust_panic_with_hook::hd6e7d786bac2c17a
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/panicking.rs:702:17
  12:     0x7f9cc28b4b01 - std[cb15343d4403b06]::panicking::begin_panic::<rustc_errors[f53c5e75797f2c2c]::ExplicitBug>::{closure#0}
  13:     0x7f9cc28b48e6 - std[cb15343d4403b06]::sys_common::backtrace::__rust_end_short_backtrace::<std[cb15343d4403b06]::panicking::begin_panic<rustc_errors[f53c5e75797f2c2c]::ExplicitBug>::{closure#0}, !>
  14:     0x7f9cc28af0a6 - std[cb15343d4403b06]::panicking::begin_panic::<rustc_errors[f53c5e75797f2c2c]::ExplicitBug>
  15:     0x7f9cc28b1566 - std[cb15343d4403b06]::panic::panic_any::<rustc_errors[f53c5e75797f2c2c]::ExplicitBug>
  16:     0x7f9cc12f73e3 - <rustc_errors[f53c5e75797f2c2c]::HandlerInner as core[99438563fdc9f911]::ops::drop::Drop>::drop
  17:     0x7f9cc0fd1268 - core[99438563fdc9f911]::ptr::drop_in_place::<rustc_session[3e6e1c7aab68e7e]::parse::ParseSess>
  18:     0x7f9cc0fc74f3 - <alloc[44a602b2dcc58bae]::rc::Rc<rustc_session[3e6e1c7aab68e7e]::session::Session> as core[99438563fdc9f911]::ops::drop::Drop>::drop
  19:     0x7f9cc0fc64bd - core[99438563fdc9f911]::ptr::drop_in_place::<rustc_interface[a7fb64d19efedbd1]::interface::Compiler>
  20:     0x7f9cc0fc5ed9 - rustc_span[752667cdfed889fa]::with_source_map::<core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>, rustc_interface[a7fb64d19efedbd1]::interface::create_compiler_and_run<core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>, rustc_driver[788d642ecae1365]::run_compiler::{closure#1}>::{closure#1}>
  21:     0x7f9cc0fc56f0 - rustc_interface[a7fb64d19efedbd1]::interface::create_compiler_and_run::<core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>, rustc_driver[788d642ecae1365]::run_compiler::{closure#1}>
  22:     0x7f9cc0fc3a61 - <scoped_tls[e6c3a7675e4d4aef]::ScopedKey<rustc_span[752667cdfed889fa]::SessionGlobals>>::set::<rustc_interface[a7fb64d19efedbd1]::interface::run_compiler<core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>, rustc_driver[788d642ecae1365]::run_compiler::{closure#1}>::{closure#0}, core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>>
  23:     0x7f9cc0fc374f - std[cb15343d4403b06]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[a7fb64d19efedbd1]::util::run_in_thread_pool_with_globals<rustc_interface[a7fb64d19efedbd1]::interface::run_compiler<core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>, rustc_driver[788d642ecae1365]::run_compiler::{closure#1}>::{closure#0}, core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>>::{closure#0}, core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>>
  24:     0x7f9cc16119b9 - <<std[cb15343d4403b06]::thread::Builder>::spawn_unchecked_<rustc_interface[a7fb64d19efedbd1]::util::run_in_thread_pool_with_globals<rustc_interface[a7fb64d19efedbd1]::interface::run_compiler<core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>, rustc_driver[788d642ecae1365]::run_compiler::{closure#1}>::{closure#0}, core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>>::{closure#0}, core[99438563fdc9f911]::result::Result<(), rustc_errors[f53c5e75797f2c2c]::ErrorGuaranteed>>::{closure#1} as core[99438563fdc9f911]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  25:     0x7f9cbef72913 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hb881e57abf2e61a2
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/alloc/src/boxed.rs:1935:9
  26:     0x7f9cbef72913 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd53432c78099d0ef
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/alloc/src/boxed.rs:1935:9
  27:     0x7f9cbef72913 - std::sys::unix::thread::Thread::new::thread_start::hc7417f6a39490db3
                               at /rustc/29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6/library/std/src/sys/unix/thread.rs:108:17
  28:     0x7f9cbecb1b43 - start_thread
                               at ./nptl/./nptl/pthread_create.c:442:8
  29:     0x7f9cbed43a00 - clone3
                               at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
  30:                0x0 - <unknown>

note: 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 1.65.0-nightly (29e4a9ee0 2022-08-10) running on x86_64-unknown-linux-gnu

note: compiler flags: --crate-type bin -C embed-bitcode=no -C debuginfo=2 -C incremental

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
end of query stack
warning: `repro` (bin "repro") generated 1 warning
error: could not compile `repro`; 1 warning emitted

Meta

rustc --version --verbose:

rustc 1.65.0-nightly (29e4a9ee0 2022-08-10)
binary: rustc
commit-hash: 29e4a9ee0253cd39e552a77f51f11f9a5f1c41e6
commit-date: 2022-08-10
host: x86_64-unknown-linux-gnu
release: 1.65.0-nightly
LLVM version: 14.0.6

Mentioning erstwhile tracking issue #53487.
Mentioning @tbodt @yaahc in connection with #99573.

[dtolnay]

"encountered unmarked API" — maybe it's that there is no #[stable] attribute on the enum variants, like there is in other stable enums? I'd have expected that to be caught during the libstd build, so we should fix whatever was supposed to catch it, not just add the attributes.

[tbodt]

Indeed, I didn't realize that enum variants also needed stable attributes.

[tbodt]

#100418