QNX: spawning a thread with a long name panics when libstd's debug assertions are enabled

[japaric]

I tried this code:

    let name = "a".repeat(1024);
    thread::Builder::new()
        .name(name)
        .spawn(|| {
            println!("it works!");
        })
        .unwrap()
        .join()
        .unwrap();

I expected to see this happen: "it works" is printed

Instead, this happened: the program panicked due to this debug assertion

rust/library/std/src/sys/unix/thread.rs

Lines 176 to 188 in 180dffb

	#[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto"))]
	pub fn set_name(name: &CStr) {
	weak! {
	fn pthread_setname_np(
	libc::pthread_t, *const libc::c_char
	) -> libc::c_int
	}
	if let Some(f) = pthread_setname_np.get() {
	let res = unsafe { f(libc::pthread_self(), name.as_ptr()) };
	debug_assert_eq!(res, 0);
	}
	}

According to the QNX documentation the maximum length a thread name can have is _NTO_THREAD_NAME_MAX. The NTO implementation of this function should truncate the thread name like, for example, the Linux implementation does. I'll submit a fix.

Meta

I used the x86_64-pc-nto-qnx710 compilation target.

rustc --version --verbose:

rustc 1.73.0-nightly (180dffba1 2023-08-14)
binary: rustc
commit-hash: 180dffba142c47240ca0d93096ce90b9fd97c8d7
commit-date: 2023-08-14
host: x86_64-unknown-linux-gnu
release: 1.73.0-nightly
LLVM version: 17.0.0

Not including a backtrace because all the reported functions in the backtrace were <unknown>