ICE with SIGSEGV when compiling simple program with -C target-cpu=native when using Mimalloc allocator

Note: The problem no longer occurs after removing target-cpu=native.

Code

fn main() { println!("Hello, world!"); }
// Yes I 100% sure this is no a joke!

Meta

rustc --version --verbose:

rustc 1.92.0 (ded5c06cf 2025-12-08)
binary: rustc
commit-hash: ded5c06cf21d2b93bffd5d884aa6e96934ee4234
commit-date: 2025-12-08
host: x86_64-unknown-linux-gnu
release: 1.92.0
LLVM version: 21.1.3

Reproduce

┌──(kris㉿KrisTHL181)-[/tmp]
└─$  LD_PRELOAD=/lib/x86_64-linux-gnu/libc.so.6 rustc a.rs -C target-cpu=native 
                                                                                                                                                                       
┌──(kris㉿KrisTHL181)-[/tmp]
└─$  LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libjemalloc.so rustc a.rs -C target-cpu=native

┌──(kris㉿KrisTHL181)-[/tmp]
└─$  LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libmimalloc.so MIMALLOC_SHOW_ERRORS=1 rustc a.rs -C target-cpu=native
mimalloc: warning: unable to allocate aligned OS memory directly, fall back to over-allocation (size: 0x10000 bytes, address: 0x7F26A6B8C000, alignment: 0x10000, commit: 1)
error: rustc interrupted by SIGSEGV, printing backtrace

/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x3c04adf) [0x7f904e404adf]
/usr/lib/x86_64-linux-gnu/libc.so.6(+0x40590) [0x7f904a440590]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/rustc(+0x12d62) [0x55f4897b8d62]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(_RNvNtCsbG23ezydE5t_18rustc_codegen_llvm9llvm_util20global_llvm_features+0x3fe) [0x7f9050bb937e]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x63b6d7a) [0x7f9050bb6d7a]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(_RNvXs3_CsbG23ezydE5t_18rustc_codegen_llvmNtB5_18LlvmCodegenBackendNtNtNtCskkDJNHb7lVI_17rustc_codegen_ssa6traits7backend14CodegenBackend13target_config+0x26) [0x7f9050bb55e6]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(_RNvNtCs5jXuXMnic4K_15rustc_interface4util17add_configuration+0x25) [0x7f9050d41225]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x6593b0d) [0x7f9050d93b0d]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x614a300) [0x7f905094a300]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x6149fe4) [0x7f9050949fe4]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x614896f) [0x7f905094896f]
/usr/lib/x86_64-linux-gnu/libc.so.6(+0x937db) [0x7f904a4937db]
/usr/lib/x86_64-linux-gnu/libc.so.6(+0x111278) [0x7f904a511278]

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 (core dumped)  LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libmimalloc.so MIMALLOC_SHOW_ERRORS=1   

Error output

(It still happens when the stack size is increased)

error: rustc interrupted by SIGSEGV, printing backtrace

/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x3c04adf) [0x7f812d204adf]
/lib/x86_64-linux-gnu/libc.so.6(+0x3fdf0) [0x7f8129449df0]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/rustc(+0x12d62) [0x56280e178d62]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(_RNvNtCsbG23ezydE5t_18rustc_codegen_llvm9llvm_util20global_llvm_features+0x3fe) [0x7f812f9b937e]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x63b6d7a) [0x7f812f9b6d7a]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(_RNvXs3_CsbG23ezydE5t_18rustc_codegen_llvmNtB5_18LlvmCodegenBackendNtNtNtCskkDJNHb7lVI_17rustc_codegen_ssa6traits7backend14CodegenBackend13target_config+0x26) [0x7f812f9b55e6]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(_RNvNtCs5jXuXMnic4K_15rustc_interface4util17add_configuration+0x25) [0x7f812fb41225]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x6593b0d) [0x7f812fb93b0d]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x614a300) [0x7f812f74a300]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x6149fe4) [0x7f812f749fe4]
/home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so(+0x614896f) [0x7f812f74896f]
/lib/x86_64-linux-gnu/libc.so.6(+0x92b7b) [0x7f812949cb7b]
/lib/x86_64-linux-gnu/libc.so.6(+0x1107b8) [0x7f812951a7b8]

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 (core dumped)  rustc -C opt-level=3 -C target-cpu=native -O a.rs -o digit_freq
--
Kernel log:
[52400.478510] rustc[421648]: segfault at 1d3180 ip 000055d8e0e5ed62 sp 00007f72fbbcf040 error 4 in rustc[11d62,55d8e0e5e000+7b000] likely on CPU 2 (core 1, socket 0)
[52400.478533] Code: 00 48 8b ac 0b b0 01 00 00 4c 39 f5 0f 85 92 06 00 00 4d 8b 67 08 89 f8 c1 e8 09 25 f8 ff 1f 00 4c 01 e0 4c 8d b3 58 03 00 00 <48> 8b 08 48 89 c8 48 c1 e8 30 48 8d 2d cd a6 28 00 4c 8b 6c c5 00

<backtrace>

GDB

┌──(kris㉿KrisTHL181)-[/tmp]
└─$  LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libmimalloc.so gdb --args rustc a.rs -C target-cpu=native              
GNU gdb (Debian 17.1-1) 17.1
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License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
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For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from rustc...
(No debugging symbols found in rustc)
⚠️ warning: Missing auto-load script at offset 0 in section .debug_gdb_scripts
of file /usr/bin/rustup.
Use `info auto-load python-scripts [REGEXP]' to list them.
(gdb) r
Starting program: /usr/bin/rustc a.rs -C target-cpu=native
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/x86_64-linux-gnu/libthread_db.so.1".
process 6005 is executing new program: /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin/rustc
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffe57bf6c0 (LWP 6011)]
[New Thread 0x7fffe4fff6c0 (LWP 6012)]
[New Thread 0x7fffe41ff6c0 (LWP 6013)]

Thread 3 "rustc" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffe4fff6c0 (LWP 6012)]
0x0000555555566d62 in free_default ()
(gdb) bt full
#0  0x0000555555566d62 in free_default ()
No symbol table info available.
#1  0x00007ffff65b937e in rustc_codegen_llvm::llvm_util::global_llvm_features ()
   from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so
No symbol table info available.
#2  0x00007ffff65b6d7a in rustc_codegen_llvm::back::write::create_informational_target_machine ()
   from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so
No symbol table info available.
#3  0x00007ffff65b55e6 in <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_ssa::traits::backend::CodegenBackend>::target_config ()
   from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so
No symbol table info available.
#4  0x00007ffff6741225 in rustc_interface::util::add_configuration ()
   from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so
No symbol table info available.
#5  0x00007ffff6793b0d in rustc_interface::interface::run_compiler::<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1} ()
   from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so
No symbol table info available.
#6  0x00007ffff634a300 in std::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()> () from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so                                                   
No symbol table info available.
#7  0x00007ffff6349fe4 in <<std::thread::Builder>::spawn_unchecked_<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} ()                                                                                           
   from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so
No symbol table info available.
#8  0x00007ffff634896f in std::sys::thread::unix::Thread::new::thread_start ()
   from /home/kris/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/librustc_driver-d31eb41759495bb2.so
No symbol table info available.
#9  0x00007fffefe937db in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:448
        ret = <optimized out>
        pd = <optimized out>
        out = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {128, -2340640383823732939, 32, 2, 140737488302560, 140737488302808, -2340629391408537398, -2340605352509742902}, 
              mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#10 0x00007fffeff11278 in __GI___clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
No locals.

Reproduce the crash with the minimal Rust program, -C target-cpu=native, and the shown LD_PRELOAD mimalloc command. Start by inspecting rustc_codegen_llvm::llvm_util::global_llvm_features, create_informational_target_machine, and target_config from the GDB backtrace. Done means rustc no longer segfaults in this configuration, with a regression test if the relevant test location is identified.