What causes "Disabling rust signal handlers failed" in uutils/coreutils?

Check environment restrictions (seccomp/SELinux) that block sigaction and relax them

Disabling rust signal handlers failed

Error message

Disabling rust signal handlers failed

What it means

The uucore proc-macro generated main calls uucore::disable_rust_signal_handlers() and unwraps with the panic message 'Disabling rust signal handlers failed'. This ensures the Rust runtime's default SIGSEGV/SIGABRT handlers (which prevent core dumps) are removed so processes dump core like GNU coreutils.

Solutions

Check environment restrictions (seccomp/SELinux) that block sigaction and relax them
If core dumps are unnecessary, build without the `signals` feature so the call is compiled out
Inspect disable_rust_signal_handlers' underlying error to identify the failing signal

Example fix

// before
uucore::disable_rust_signal_handlers().expect("Disabling rust signal handlers failed");
// after
if let Err(e) = uucore::disable_rust_signal_handlers() { eprintln!("warning: {e}"); }

Defensive patterns

Strategy: try-catch

Try / catch

// in your own bootstrap, avoid expect:
if let Err(e) = uucore::disable_rust_signal_handlers() {
    eprintln!("warning: could not disable rust signal handlers: {e}");
}

Prevention

Test utilities inside the same container/seccomp profile used in production
Enable core dumps (ulimit -c) to notice handler issues early
Build without the `signals` feature if signal-handler manipulation is not required

When it happens

Trigger: Running any utility built with the `signals` feature on unix where disable_rust_signal_handlers returns Err — e.g. the runtime failed to reset a signal handler (sigaction failure) at startup.

Common situations: Restricted environments (seccomp/SELinux profiles, containers) blocking signal syscalls; exotic unix platforms where the handler-reset call fails.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

AI-assisted analysis of uutils/coreutils@92995feca2 (2026-09-20). Data as JSON: /api/errors/88d24adeeaa347b6. Report an issue: GitHub.

Appendix: source

Thrown at src/uucore_procs/src/lib.rs:53

        // before main() to capture whether SIGPIPE was ignored by the parent process.
        #[cfg(all(#signals, unix, not(any(target_os = "fuchsia", target_os = "haiku"))))]
        uucore::init_startup_state_capture!();

        pub fn uumain(args: impl uucore::Args) -> i32 {
            #stream

            // Restore SIGPIPE to default if it wasn't explicitly ignored by parent.
            // The Rust runtime ignores SIGPIPE, but we need to respect the parent's
            // signal disposition for proper pipeline behavior (GNU compatibility).
            // needed even for true --version
            #[cfg(all(unix, not(any(target_os = "fuchsia", target_os = "haiku"))))]
            if !uucore::signals::sigpipe_was_ignored() {
                let _ = uucore::signals::enable_pipe_errors();
            }

            // disable rust signal handlers (otherwise processes don't dump core after e.g. one SIGSEGV)
            #[cfg(all(#signals, unix))]
            uucore::disable_rust_signal_handlers().expect("Disabling rust signal handlers failed");
            let result = uumain(args);
            match result {
                Ok(()) => uucore::error::get_exit_code(),
                Err(e) => {
                    let s = format!("{e}");
                    if s != "" {
                        uucore::show_error!("{s}");
                    }
                    if e.usage() {
                        use std::io::{stderr, Write as _};
                        let _ = writeln!(stderr(),"Try '{} --help' for more information.", uucore::execution_phrase());
                    }
                    e.code()
                }
            }
        }
    );

View on GitHub (pinned to 92995feca2)