jdx/mise · error

task executor initialized

Error message

task executor initialized

What it means

This panic is an internal invariant check in mise's task runner. After tool installation completes, `setup_executor()` must have populated `self.executor`; `parallelize_tasks` then unwraps it to run preflight validation on every scheduled task. If the executor is `None` at this point, a refactoring or ordering bug in the run pipeline has occurred — users cannot trigger it via normal CLI input.

Solutions

1. Re-run the same mise command with `MISE_DEBUG=1` to capture the stack trace and file a mise bug report with the command and trace
2. Check that no local mise wrapper, shim, or patched build is running stale or modified code; rebuild with `mise run build`
3. Inspect `setup_executor()` in src/cli/run.rs to confirm it assigns `self.executor` on every success path
4. Upgrade to the latest mise release in case this was a regression already fixed upstream

Example fix

// before
let executor = self.executor.as_ref().expect("task executor initialized");
// after
let Some(executor) = self.executor.as_ref() else {
    bail!("internal error: task executor was not initialized; please report this bug");
};

if std::env::var("MISE_DEBUG").is_ok() { eprintln!("repro: mise run <task>"); }
// For plugin/CI authors: assert the binary is unmodified
// cargo build && target/debug/mise run <task>  # compare against released mise

// Panic, not Result: catch it only to improve the report
let output = std::process::Command::new("mise").args(["run", "build"]).output()?;
if !output.status.success() && String::from_utf8_lossy(&output.stderr).contains("task executor initialized") {
    eprintln!("mise internal bug — file an issue with MISE_DEBUG=1 output");
}

When it happens

Trigger: Only reachable if `setup_executor()` silently succeeds without setting `self.executor`, or if code is reordered so `parallelize_tasks` runs before `setup_executor()`. Also triggered if a developer bypasses the standard `run` pipeline (e.g. a new entry point calling `parallelize_tasks` directly).

Common situations: Seen during development of mise itself: someone adds a code path that returns early from setup with `Ok(())` while skipping executor assignment, or a contributor moves the preflight loop before executor creation.

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

• executor must be initialized before running tasks
• artifact directory was initialized
• command wait must complete
• executor must be initialized before displaying cache stats
• generated mise usage spec

AI-assisted analysis of jdx/mise@afd2eddd3a (2026-09-09). Data as JSON: /api/errors/508ed8f41defbe5f. Report an issue: GitHub.

Appendix: source

Thrown at src/cli/run.rs:902

        let tasks = self.prepare_tasks(&config, tasks).await?;
        let num_tasks = tasks.all().count();

        // Step 2: Setup output handler and validate tasks
        self.setup_output_and_validate(&tasks)?;
        self.output = Some(self.output(None));

        // Step 3: Install tools needed by tasks
        if !self.skip_tools {
            self.install_task_tools(&mut config, &tasks, &previewed_tools)
                .await?;
        }

        // Step 4: Create TaskExecutor after tool installation
        self.setup_executor()?;

        // Validate every scheduled invocation before starting the scheduler so
        // an invalid parent or dependency cannot run any task commands first.
        let executor = self.executor.as_ref().expect("task executor initialized");
        for task in tasks.all() {
            executor
                .preflight_task_usage(&config, task)
                .await
                .wrap_err_with(|| format!("failed to validate task {}", task.name))?;
        }

        // Disable exit-on-ctrl-c so tasks can handle SIGINT gracefully
        ctrlc::exit_on_ctrl_c(false);

        let timer = std::time::Instant::now();
        let this = Arc::new(self);
        let config = config.clone();

        // Step 5: Initialize scheduler and run tasks
        let mut scheduler = crate::task::task_scheduler::Scheduler::new(this.jobs());
        let main_deps = Arc::new(Mutex::new(tasks));

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