ICE - unsafe precondition violation in slice::from_raw_parts_mut on powerpc64-unknown-linux-musl
Open
Nobody has claimed this yet.
C-bug
I-crash
O-musl
O-PowerPC
T-compiler
- Dominant language
- Rust
- Stars
- 119k
- Forks
- 16.1k
- PR merge metrics
- PR metrics pending
Description
Code
Pretty much any Rust code that isn't an empty fn main() {}. For example, tests/ui/traits/map-types.rs:
use std::collections::HashMap;
trait Map<K, V>
{
fn get(&self, k: K) -> V { panic!() }
}
impl<K, V> Map<K, V> for HashMap<K, V> {}
// Test that trait types printed in error msgs include the type arguments.
fn main() {
let x: Box<HashMap<isize, isize>> = HashMap::new().into();
let x: Box<dyn Map<isize, isize>> = x;
let y: Box<dyn Map<usize, isize>> = Box::new(x);
//~^ ERROR `Box<dyn Map<isize, isize>>: Map<usize, isize>` is not satisfied
}
Meta
rustc --version --verbose:
rustc 1.89.0-dev
binary: rustc
commit-hash: unknown
commit-date: unknown
host: powerpc64-unknown-linux-musl
release: 1.89.0-dev
LLVM version: 20.1.5
Error output
thread 'rustc' panicked at /usr/lib/rustlib/src/rust/library/core/src/panicking.rs:226:5:
unsafe precondition(s) violated: slice::from_raw_parts_mut requires the pointer to be aligned and non-null, and the total size of the slice not to exceed `isize::MAX`
This indicates a bug in the program. This Undefined Behavior check is optional, and cannot be relied on for safety.
Backtrace
stack backtrace:
0: 0x3998da863028 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h6b7a16c5580db569
1: 0x3998da8c49e8 - core::fmt::write::h412196edc8a0bac6
2: 0x3998da852710 - std::io::Write::write_fmt::h601d56a19420a788
3: 0x3998da862ea0 - std::sys::backtrace::BacktraceLock::print::h17bff0d3f977264e
4: 0x3998da867bf8 - std::panicking::default_hook::{{closure}}::ha5fc841ae5cd04eb
5: 0x3998da867884 - std::panicking::default_hook::h87486f900b0501f7
6: 0x3998d58bedfc - <std[907ab836018c748a]::panicking::default_hook as core[a1430d4ba98a45c9]::ops::function::Fn<(&std[907ab836018c748a]::panic::PanicHookInfo,)>>::call
at /usr/lib/rustlib/src/rust/library/core/src/ops/function.rs:79:5
7: 0x3998d58d363c - <alloc[8a3938205d7c8a1c]::boxed::Box<dyn for<'a, 'b> core[a1430d4ba98a45c9]::ops::function::Fn<(&'a std[907ab836018c748a]::panic::PanicHookInfo<'b>,), Output = ()> + core[a1430d4ba98a45c9]::marker::Send + core[a1430d4ba98a45c9]::marker::Sync> as core[a1430d4ba98a45c9]::ops::function::Fn<(&std[907ab836018c748a]::panic::PanicHookInfo,)>>::call
at /usr/lib/rustlib/src/rust/library/alloc/src/boxed.rs:1980:9
8: 0x3998d58d372c - {closure#1}
at /home/adrian/rust/compiler/rustc_driver_impl/src/lib.rs:1362:17
9: 0x3998d58d372c - call<(&(dyn core::ops::function::Fn<(&std::panic::PanicHookInfo), Output=()> + core::marker::Send + core::marker::Sync), &std::panic::PanicHookInfo), rustc_driver_impl::install_ice_hook::{closure_env#1}, alloc::alloc::Global>
at /usr/lib/rustlib/src/rust/library/alloc/src/boxed.rs:1980:9
10: 0x3998d58bebcc - std[907ab836018c748a]::panicking::update_hook::<alloc[8a3938205d7c8a1c]::boxed::Box<rustc_driver_impl[3cb4f2869d0b6653]::install_ice_hook::{closure#1}>>::{closure#0}
at /usr/lib/rustlib/src/rust/library/std/src/panicking.rs:243:47
11: 0x3998da868d38 - std::panicking::rust_panic_with_hook::h01dad58d372d72b9
12: 0x3998da86875c - std::panicking::begin_panic_handler::{{closure}}::h0921d5db50e2f3db
13: 0x3998da8636dc - std::sys::backtrace::__rust_end_short_backtrace::h2a52412d337f6395
14: 0x3998da868200 - __rustc[820ce06c06146c08]::rust_begin_unwind
15: 0x3998da8bf4e4 - core::panicking::panic_nounwind_fmt::hea1385ba292cdf61
16: 0x3998da8bf5c4 - core::panicking::panic_nounwind::h910baf6dda7e5e34
17: 0x3998da6aee7c - precondition_check
at /usr/lib/rustlib/src/rust/library/core/src/ub_checks.rs:68:21
18: 0x3998da6aee7c - from_raw_parts_mut<alloc::boxed::Box<rustc_ast::ast::Item<rustc_ast::ast::ItemKind>, alloc::alloc::Global>>
at /usr/lib/rustlib/src/rust/library/core/src/ub_checks.rs:75:17
19: 0x3998da6aee7c - as_mut_slice<alloc::boxed::Box<rustc_ast::ast::Item<rustc_ast::ast::ItemKind>, alloc::alloc::Global>>
at /home/adrian/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/thin-vec-0.2.14/src/lib.rs:1047:18
20: 0x3998da6aee7c - deref_mut<alloc::boxed::Box<rustc_ast::ast::Item<rustc_ast::ast::ItemKind>, alloc::alloc::Global>>
at /home/adrian/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/thin-vec-0.2.14/src/lib.rs:1711:9
21: 0x3998da6aee7c - drop_non_singleton<alloc::boxed::Box<rustc_ast::ast::Item<rustc_ast::ast::ItemKind>, alloc::alloc::Global>>
at /home/adrian/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/thin-vec-0.2.14/src/lib.rs:1684:41
22: 0x3998d588c7cc - drop<alloc::boxed::Box<rustc_ast::ast::Item<rustc_ast::ast::ItemKind>, alloc::alloc::Global>>
at /home/adrian/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/thin-vec-0.2.14/src/lib.rs:1696:13
23: 0x3998d588c7cc - drop_in_place<thin_vec::ThinVec<alloc::boxed::Box<rustc_ast::ast::Item<rustc_ast::ast::ItemKind>, alloc::alloc::Global>>>
at /usr/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:524:1
24: 0x3998d588c7cc - drop_in_place<rustc_ast::ast::Crate>
at /usr/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:524:1
25: 0x3998d58c5d80 - drop_in_place<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>>
at /usr/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:524:1
26: 0x3998d58c5060 - enter<rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, core::option::Option<rustc_interface::queries::Linker>>
at /home/adrian/rust/compiler/rustc_middle/src/ty/context.rs:1497:5
27: 0x3998d58c5060 - create_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt::{closure#2}::{closure_env#0}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>>
at /home/adrian/rust/compiler/rustc_middle/src/ty/context.rs:1717:9
28: 0x3998d581aaf4 - {closure#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>
at /home/adrian/rust/compiler/rustc_interface/src/passes.rs:873:9
29: 0x3998d581aaf4 - call_once<rustc_interface::passes::create_and_enter_global_ctxt::{closure_env#2}<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>, (&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy, alloc::alloc::Global>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2})>
at /usr/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5
30: 0x3998d58d2f90 - call_once<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy, alloc::alloc::Global>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}), dyn core::ops::function::FnOnce<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy, alloc::alloc::Global>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}), Output=core::option::Option<rustc_interface::queries::Linker>>, alloc::alloc::Global>
at /usr/lib/rustlib/src/rust/library/alloc/src/boxed.rs:1966:9
31: 0x3998d58195f4 - create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure_env#2}>
at /home/adrian/rust/compiler/rustc_interface/src/passes.rs:914:5
32: 0x3998d581896c - {closure#0}
at /home/adrian/rust/compiler/rustc_driver_impl/src/lib.rs:338:22
33: 0x3998d581896c - {closure#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>
at /home/adrian/rust/compiler/rustc_interface/src/interface.rs:526:80
34: 0x3998d581896c - call_once<(), rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>
at /usr/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:272:9
35: 0x3998d581896c - do_call<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>, ()>
at /usr/lib/rustlib/src/rust/library/std/src/panicking.rs:589:40
36: 0x3998d581896c - try<(), core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>>
at /usr/lib/rustlib/src/rust/library/std/src/panicking.rs:552:19
37: 0x3998d581896c - catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<rustc_interface::interface::run_compiler::{closure#1}::{closure_env#0}<(), rustc_driver_impl::run_compiler::{closure_env#0}>>, ()>
at /usr/lib/rustlib/src/rust/library/std/src/panic.rs:359:14
38: 0x3998d5815778 - {closure#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>
at /home/adrian/rust/compiler/rustc_interface/src/interface.rs:526:23
39: 0x3998d5815778 - {closure#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>
at /home/adrian/rust/compiler/rustc_interface/src/util.rs:199:17
40: 0x3998d5815778 - {closure#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>
at /home/adrian/rust/compiler/rustc_interface/src/util.rs:153:24
41: 0x3998d5815778 - set<rustc_span::SessionGlobals, rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>
at /home/adrian/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/scoped-tls-1.0.1/src/lib.rs:137:9
42: 0x3998d58fe9a4 - create_session_globals_then<(), rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>>
at /home/adrian/rust/compiler/rustc_span/src/lib.rs:144:5
43: 0x3998d58f5b10 - {closure#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>
at /home/adrian/rust/compiler/rustc_interface/src/util.rs:149:17
44: 0x3998d58f5b10 - __rust_begin_short_backtrace<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>
at /usr/lib/rustlib/src/rust/library/std/src/sys/backtrace.rs:152:18
45: 0x3998d58f4cc0 - {closure#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>
at /usr/lib/rustlib/src/rust/library/std/src/thread/mod.rs:559:17
46: 0x3998d58f4cc0 - call_once<(), std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>>
at /usr/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:272:9
47: 0x3998d58f4cc0 - do_call<core::panic::unwind_safe::AssertUnwindSafe<std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>>, ()>
at /usr/lib/rustlib/src/rust/library/std/src/panicking.rs:589:40
48: 0x3998d58f4cc0 - try<(), core::panic::unwind_safe::AssertUnwindSafe<std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>>>
at /usr/lib/rustlib/src/rust/library/std/src/panicking.rs:552:19
49: 0x3998d58f4cc0 - catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<std::thread::{impl#0}::spawn_unchecked_::{closure#1}::{closure_env#0}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>>, ()>
at /usr/lib/rustlib/src/rust/library/std/src/panic.rs:359:14
50: 0x3998d58f4cc0 - {closure#1}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>
at /usr/lib/rustlib/src/rust/library/std/src/thread/mod.rs:557:30
51: 0x3998d58f4cc0 - call_once<std::thread::{impl#0}::spawn_unchecked_::{closure_env#1}<rustc_interface::util::run_in_thread_with_globals::{closure#0}::{closure_env#0}<rustc_interface::util::run_in_thread_pool_with_globals::{closure_env#0}<rustc_interface::interface::run_compiler::{closure_env#1}<(), rustc_driver_impl::run_compiler::{closure_env#0}>, ()>, ()>, ()>, ()>
at /usr/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5
52: 0x3998da86c670 - std::sys::pal::unix::thread::Thread::new::thread_start::h62bfbd8292ec418b
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: please make sure that you have updated to the latest nightly
note: please attach the file at `/home/adrian/rust/rustc-ice-2025-06-10T23_26_31-12576.txt` to your bug report
note: compiler flags: -C target-feature=-crt-static
I encountered this when running the testsuite natively, weirdly enough my stage0 compiler (rustc 1.88.0-nightly (d6a325d93 2025-05-03), cross compiled from x86_64 and dynamically linked) never crashes, but the natively compiled stage1 does. I immediately thought this may be an allocator issue, since my musl libc is patched to use mimalloc, but nope, mallocng (aka unmodified, "stock" musl malloc) musl also crashes.
The crash manifests in every couple of invocations - it sometimes compiles just fine, other times it will trigger the unsafe precondition evaluation, other times it will exit with SIGSEGV and no error message.
I'll try some older versions to see if this was a recent regression.
Things I tested so far: beta branch - also occurs
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the ICE using the example in tests/ui/traits/map-types.rs on the powerpc64-unknown-linux-musl target with the reported rustc version. Start with the backtrace entries in thin-vec's src/lib.rs and determine the compiler path that triggers the violation; done means the crash is fixed and a regression test covers it.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100