SIGSEGV when using incremental, '--test' and realtime sanitizer #149250
Description
I tried this code:
#![feature(sanitize)]
fn main() {
let result = add(2, 2);
assert_eq!(result, 4)
}
#[sanitize(realtime = "nonblocking")]
pub fn add(left: u64, right: u64) -> u64 {
left + right
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test() {
let result = add(2, 2);
assert_eq!(result, 4);
}
}with rustc src/main.rs --test -C incremental={some folder} -Zsanitizer=realtime
If either test or incremental or realtime sanitizer command line flag is removed it doesn't crash anymore. From the backtrace it looks like a llvm bug, but i tried emit=llvm-ir and then calling llc on that, but that seemed to work fine. It could of couse still be a llvm bug.
I expected to see this happen: compiles
Instead, this happened: SIGSEGV
Meta
rustc --version --verbose:
rustc 1.93.0-nightly (94b49fd99 2025-11-22)
binary: rustc
commit-hash: 94b49fd998d6723e0a9240a7cff5f9df37b84dd8
commit-date: 2025-11-22
host: aarch64-apple-darwin
release: 1.93.0-nightly
LLVM version: 21.1.5
Backtrace
error: rustc interrupted by SIGSEGV, printing backtrace
0 librustc_driver-16b1f550720647e6.dy 0x0000000110dbab8c _RNvNtCs99FapbrAgm6_17rustc_driver_impl14signal_handler17print_stack_trace + 140
1 libsystem_platform.dylib 0x000000019c4416a4 _sigtramp + 56
2 librustc_driver-16b1f550720647e6.dy 0x00000001141cda58 _ZL27insertCallBeforeInstructionRN4llvm8FunctionERNS_11InstructionEPKcNS_8ArrayRefIPNS_5ValueEEE + 316
3 librustc_driver-16b1f550720647e6.dy 0x00000001141cd5e8 _ZN4llvm21RealtimeSanitizerPass3runERNS_6ModuleERNS_15AnalysisManagerIS1_JEEE + 388
4 librustc_driver-16b1f550720647e6.dy 0x00000001158d97a0 _ZN4llvm11PassManagerINS_6ModuleENS_15AnalysisManagerIS1_JEEEJEE3runERS1_RS3_ + 280
5 librustc_driver-16b1f550720647e6.dy 0x0000000115ab6c3c LLVMRustOptimize + 10804
6 librustc_driver-16b1f550720647e6.dy 0x0000000110a95400 _RNvNtNtCscmi45mdQtkA_18rustc_codegen_llvm4back5write13llvm_optimize + 3268
7 librustc_driver-16b1f550720647e6.dy 0x0000000110ad5028 _RNvXs1_Cscmi45mdQtkA_18rustc_codegen_llvmNtB5_18LlvmCodegenBackendNtNtNtCsezIrwaAAZdA_17rustc_codegen_ssa6traits5write19WriteBackendMethods8optimize + 460
8 librustc_driver-16b1f550720647e6.dy 0x0000000110a141c0 _RINvNtNtCsezIrwaAAZdA_17rustc_codegen_ssa4back5write26execute_optimize_work_itemNtCscmi45mdQtkA_18rustc_codegen_llvm18LlvmCodegenBackendEB1i_ + 152
9 librustc_driver-16b1f550720647e6.dy 0x0000000110a1508c _RINvNtNtCskpKSKVtn3H6_3std3sys9backtrace28___rust_begin_short_backtraceNCINvXs0_Cscmi45mdQtkA_18rustc_codegen_llvmNtB1g_18LlvmCodegenBackendNtNtNtCsezIrwaAAZdA_17rustc_codegen_ssa6traits7backend19ExtraBackendMethods18spawn_named_threadNCINvNtNtB2k_4back5write10spawn_workB1O_E0uE0uEB1g_ + 176
10 librustc_driver-16b1f550720647e6.dy 0x0000000110a49ad0 _RNSNvYNCINvMNtCskpKSKVtn3H6_3std6threadNtBa_7Builder16spawn_unchecked_NCINvXs0_Cscmi45mdQtkA_18rustc_codegen_llvmNtB1f_18LlvmCodegenBackendNtNtNtCsezIrwaAAZdA_17rustc_codegen_ssa6traits7backend19ExtraBackendMethods18spawn_named_threadNCINvNtNtB2j_4back5write10spawn_workB1N_E0uE0uEs_0INtNtNtCshcx3WXiymsJ_4core3ops8function6FnOnceuE9call_once6vtableB1f_ + 456
11 librustc_driver-16b1f550720647e6.dy 0x0000000112d56424 _ZN3std3sys6thread4unix6Thread3new12thread_start17h59b69fa380c42a3cE + 52
12 libsystem_pthread.dylib 0x000000019c407bc8 _pthread_start + 136
13 libsystem_pthread.dylib 0x000000019c402b80 thread_start + 8
note: we would appreciate a report at https://github.com/rust-lang/rust
help: you can increase rustc's stack size by setting RUST_MIN_STACK=16777216
zsh: segmentation fault /Users/_/.rustup/toolchains/nightly-aarch64-apple-darwin/bin/rustc