"Illegal instruction" when running release build

[SlaynAndKorpil]

When running this code with cargo run --release, it prints Illegal instruction and immedialy exits with error code 132. This only happens when running the release build, the debug build created by cargo build just runs endlessly as expected.

use std::thread;

fn main() {
    let thread = thread::spawn(move || {
        let x = 0isize;
        loop {
            x % 1;
        }
    });

    thread.join().unwrap();
}

This happens when x is of any signed integer type. When I replace the content of the loop with 0isize % 1;, the error does not occur. Using something like while true instead of loop leads to the same error.

I did not modify the Cargo.toml generated by cargo new:

[package]
name = "bug"
version = "0.1.0"
authors = ["felix <felix.a.lehner@googlemail.com>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]

Meta

I have tested this problem on two Linux machines (uname -a):
Linux wheatly 4.19.0-14-amd64 #1 SMP Debian 4.19.171-2 (2021-01-30) x86_64 GNU/Linux
and Linux raspberrypi 5.4.79-v7l+ #1373 SMP Mon Nov 23 13:27:40 GMT 2020 armv7l GNU/Linux
both running the same rust version:
rustc --version --verbose:

rustc 1.50.0 (cb75ad5db 2021-02-10)
binary: rustc
commit-hash: cb75ad5db02783e8b0222fee363c5f63f7e2cf5b
commit-date: 2021-02-10
host: x86_64-unknown-linux-gnu
release: 1.50.0

[ehuss]

Thanks for the report! Infinite loops are undefined behavior in LLVM, which can result in anything happening. This is a known issue, closing as a duplicate of #28728.