Segmentation fault with sequence of conditionally compiled tracing debug calls on certain archs

[s-m-e]

Bug Report

Minimal example, it requires a project with a few optional features (e.g. ddd and hhh disabled, rest enabled):

use std::process::ExitCode;

use tracing::{debug, info, Level};
use tracing_subscriber;

fn main() -> ExitCode {
    tracing_subscriber::fmt()
        .json()
        .with_max_level(Level::DEBUG)
        .with_current_span(false)
        .init();

    // start

    #[cfg(feature = "aaa")]
    debug!(feature = "aaa");
    #[cfg(feature = "bbb")]
    debug!(feature = "bbb");
    #[cfg(feature = "ccc")]
    debug!(feature = "ccc");
    #[cfg(feature = "ddd")]
    debug!(feature = "ddd");
    #[cfg(feature = "eee")]
    debug!(feature = "eee");
    #[cfg(feature = "fff")]
    debug!(feature = "fff");
    #[cfg(feature = "hhh")]
    debug!(feature = "hhh");

    // end

    ExitCode::from(0)
}

Version

RUST_VERSION=1.87.0
RUSTUP_VERSION=1.28.2

    │   │   │   └── tracing v0.1.41
    │   │   │       ├── tracing-attributes v0.1.28 (proc-macro)
    │   │   │       └── tracing-core v0.1.33
    ├── tracing v0.1.41 (*)
    ├── tracing-subscriber v0.3.19
    │   ├── tracing-core v0.1.33 (*)
    │   ├── tracing-log v0.2.0
    │   │   └── tracing-core v0.1.33 (*)
    │   └── tracing-serde v0.2.0
    │       └── tracing-core v0.1.33 (*)

Platform

Bug does not trigger on Linux x86-64 with glibc & musl and recent Linux environments (Ubuntu LTS 22, 24, equivalent Debians, etc).

Bug does trigger on ARM (v7 / 32bit, compiled on x86-64) with glibc (cargo build --release --target arm-unknown-linux-gnueabi), Linux 5.10.213-xilinx 1 SMP PREEMPT armv7l.

Description

On the described target platform, the above code segfaults right out of the gate - the binary appears to be broken. Any code prior to start also does not get executed. If code between start and end is removed, it works.