What causes "Codex command is empty" in BigPizzaV3/CodexPlusPlus?

Ensure build_codex_command always begins with the codex executable path

Codex command is empty

Error message

Codex command is empty

What it means

Like the macOS counterpart, launch_codex (non-macOS path) builds the Codex command via build_codex_command and requires a first element as the executable. An empty command vector means the builder produced nothing to run, so the launch fails early with this error.

Solutions

Ensure build_codex_command always begins with the codex executable path
Reset custom launch arguments/command overrides to defaults
Verify the configured Codex CLI path is non-empty in settings

Example fix

// before
let command: Vec<String> = Vec::new();
// after
let mut command = vec![codex_executable.to_string_lossy().into_owned()];
command.extend(extra_args.iter().cloned());

Defensive patterns

Strategy: validation

Validate before calling

let command = build_codex_command(app_dir, debug_port, &launch_extra_args);
if command.is_empty() {
    return Err("launcher produced an empty command; report this bug".into());
}

Prevention

Add a unit test asserting build_codex_command always includes the executable
Keep the codex executable path non-empty in settings
Guard custom command overrides so they cannot erase the first element

When it happens

Trigger: build_codex_command or the custom-command variant returns an empty Vec — a builder regression or configuration that eliminates the executable token.

Common situations: Misconfigured custom codex command; developer-modified builder dropping the executable; empty launch args handling bug.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

AI-assisted analysis of BigPizzaV3/CodexPlusPlus@b1ed92e5e4 (2026-09-19). Data as JSON: /api/errors/c02f63b065e5e91a. Report an issue: GitHub.

Appendix: source

Thrown at crates/codex-plus-core/src/launcher.rs:987

                command,
                wait_strategy: ProcessWaitStrategy::ExternalWaitCommand,
                macos_cleanup_policy: Some(cleanup_policy),
            });
        }

        let command = if let Some(inspector_port) = native_menu_inspector_port {
            build_codex_command_with_native_menu_inspector(
                app_dir,
                debug_port,
                inspector_port,
                &launch_extra_args,
            )
        } else {
            build_codex_command(app_dir, debug_port, &launch_extra_args)
        };
        let executable = command
            .first()
            .ok_or_else(|| anyhow::anyhow!("Codex command is empty"))?;
        let mut child_command = Command::new(executable);
        child_command
            .args(&command[1..])
            .stdout(Stdio::null())
            .stderr(Stdio::null());
        #[cfg(windows)]
        child_command.creation_flags(crate::windows_integration::CREATE_NO_WINDOW);
        let child = child_command
            .spawn()
            .with_context(|| format!("failed to launch Codex executable {executable}"))?;
        *self.child.lock().await = Some(child);
        if let Some(inspector_port) = native_menu_inspector_port {
            start_native_menu_localizer(inspector_port);
        }
        Ok(CodexLaunch::Process {
            command,
            wait_strategy: ProcessWaitStrategy::TrackedChild,
            macos_cleanup_policy: None,

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