Compiler panicked at 'is_signed on non-scalar ABI' during const evaluation on windows-sys crate

[AqourSoro]

Code

The Internal Compiler Error (ICE) was triggered during compilation of the crate windows-sys version 0.59.0, as a dependency of evcxr_jupyter. Minimal reproduction command:

cargo install --locked evcxr_jupyter

Currently, this is the smallest reliable reproduction step found.

Meta

Output of rustc --version --verbose:

rustc 1.85.1 (4eb161250 2025-03-15)
binary: rustc
commit-hash: 4eb161250e340c8f48f66e2b929ef4a5bed7c181
commit-date: 2025-03-15
host: x86_64-pc-windows-msvc
release: 1.85.1
LLVM version: 18.1.3

Error output

thread 'rustc' panicked at /rustc/4eb161250e340c8f48f66e2b929ef4a5bed7c181\compiler\rustc_abi\src\lib.rs:1446:18:
`is_signed` on non-scalar ABI ScalarPair(Union { value: Int(I8, false) }, Initialized { value: Int(I8, false), valid_range: 21301445860939404079836335616267649024..=105358827881679071900638810302764611136 })

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 1.85.1 (4eb161250 2025-03-15) running on x86_64-pc-windows-msvc

note: compiler flags: --crate-type lib -C opt-level=3 -C embed-bitcode=no -C strip=debuginfo

query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `Win32::Foundation::ERROR_FLT_NO_HANDLER_DEFINED`
#1 [eval_to_const_value_raw] simplifying constant for the type system `Win32::Foundation::ERROR_FLT_NO_HANDLER_DEFINED`
end of query stack

error: could not compile `windows-sys` (lib)

Caused by:
  process didn't exit successfully: `rustc.exe --crate-name windows_sys --edition=2021 windows-sys-0.59.0\src\lib.rs --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no --warn=rust_2018_idioms --warn=unexpected_cfgs --warn=missing_docs` (exit code: 0xc0000005, STATUS_ACCESS_VIOLATION)

error: failed to compile `evcxr_jupyter v0.19.0`, intermediate artifacts can be found at `C:\Users\97175\AppData\Local\Temp\cargo-installLYwVOH`.
To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.

Backtrace

stack backtrace:
0: std::backtrace_rs::backtrace::dbghelp64::trace
1: std::backtrace_rs::backtrace::trace_unsynchronized
2: std::sys::backtrace::_print_fmt
3: std::sys::backtrace::impl$0::print::impl$0::fmt
4: core::fmt::rt::Argument::fmt
5: core::fmt::write
6: std::io::Write::write_fmt
7: std::sys::backtrace::BacktraceLock::print
8: std::panicking::default_hook::closure$1
9: std::panicking::default_hook
10: core::slice::sort::unstable::heapsort::heapsort
11: alloc::boxed::impl$30::call
12: std::panicking::rust_panic_with_hook
13: std::panicking::begin_panic_handler::closure$0
14: std::sys::backtrace::__rust_end_short_backtrace
15: std::panicking::begin_panic_handler
16: core::panicking::panic_fmt
17: rustc_const_eval::interpret::eval_context::InterpCx<_>::storage_live_dyn::is_very_trivially_sized
18: rustc_const_eval::const_eval::eval_queries::eval_to_allocation_raw_provider
19: rustc_query_impl::plumbing::query_key_hash_verify_all
20: rustc_query_system::query::plumbing::try_execute_query
21: rustc_query_impl::plumbing::query_key_hash_verify_all
22: rustc_const_eval::const_eval::eval_queries::eval_to_const_value_raw_provider
23: rustc_query_impl::plumbing::query_key_hash_verify_all
24: rustc_query_system::query::plumbing::try_execute_query
25: rustc_query_impl::plumbing::query_key_hash_verify_all
26: hashbrown::raw::RawTable::reserve_rehash
27: rustc_hir_analysis::check_crate
28: rustc_interface::passes::resolver_for_lowering_raw
29: rustc_interface::passes::analysis
30: alloc::sync::Arc<rustc_session::config::OutputFilenames>::drop_slow
31: rustc_query_system::query::plumbing::try_execute_query
32: rustc_query_impl::query_system
33: rustc_interface::util::run_in_thread_with_globals
34: rustc_interface::util::run_in_thread_pool_with_globals
35: rustc_interface::interface::run_compiler
36: alloc::boxed::impl$28::call_once
37: std::sys::pal::windows::thread::impl$0::new::thread_start
38: BaseThreadInitThunk
39: RtlUserThreadStart

---

This issue was found while attempting to compile the evcxr_jupyter crate on Windows (x86_64-pc-windows-msvc) environment. It seems specifically related to compiling the windows-sys crate, version 0.59.0, using Rust 1.85.1. The error consistently reproduces with optimization flags enabled (-C opt-level=3) and causes the compiler to panic due to an internal error in const evaluation.

A minimized version was not yet produced given the complexity, but the reproduction above is reliable and clear.

Please let me know if any additional information or testing is required.

[moxian]

I am unable to reproduce this with rustc 1.85.1 (4eb161250 2025-03-15) on Win 10 22H2 19045.5608 (neither via cargo install --locked nor via grabbing the evcxr_jupyter crate manually and running cargo build --release)

What is your OS version?

Does it work on an older rustc? If so, can you try bisecting rust version that introduced it (https://github.com/rust-lang/cargo-bisect-rustc)?

@rustbot label: +A-const-eval

[AqourSoro]

My OS is Windows 11 Version 24H2 (OS Build 26100.3476).

I attempted to downgrade to rustc 1.84.1 (e71f9a9a9 2025-01-27) to bisect the regression, but evcxr_jupyter (or one of its dependencies) requires edition2024, which is not supported on 1.84.1. Thus, I cannot build the crate on older toolchains.

I've tested rustc 1.85.0 (4d91de4e4 2025-02-17) and rustc 1.85.1 (4eb161250 2025-03-15), and both produce the same error.

I've also tried this on another computer with Windows 11 Version 24H2 (OS Build 26100.3194) and rustc 1.85.1 (4eb161250 2025-03-15), it works just fine, seems like an issue related to windows system update.

[moxian]

As a minimization attempt, can you try building an empty project with this Cargo.toml? (I obtained the list of features from $env:RUSTC_BOOTSTRAP=1; cargo build -Zunstable-options --unit-graph on my machine, I would hope(?) they are the same for you)

[package]
name = "mycrate"
version = "0.1.0"
edition = "2018"

[dependencies]
version = "=0.59.0"
features = [
    "Win32",
    "Win32_Foundation",
    "Win32_Security",
    "Win32_Storage",
    "Win32_Storage_FileSystem",
    "Win32_System",
    "Win32_System_Console",
    "Win32_System_IO",
    "Win32_System_ProcessStatus",
    "Win32_System_SystemInformation",
    "Win32_System_Threading",
    "Win32_System_WindowsProgramming",
    "default",
]