What causes "Failed to get stdin" in Zackriya-Solutions/meetily?

Confirm the Command builder sets .stdin(Stdio::piped()).stdout(Stdio::piped()) before .spawn()

Zackriya-Solutions/meetily · error · anyhow::Error

Failed to get stdin

Error message

Failed to get stdin

What it means

After spawning the sidecar, the code takes the child's stdin pipe; take() returns None only when the child was not spawned with Stdio::piped() for stdin. The current spawn path explicitly sets .stdin(Stdio::piped()), so this is an invariant check that should be unreachable unless the spawn configuration is broken.

Source

Thrown at frontend/src-tauri/src/summary/summary_engine/sidecar.rs:313

        command
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .stderr(Stdio::inherit()) // Log stderr to main process
            .env("LLAMA_IDLE_TIMEOUT", self.idle_timeout_secs.to_string());

        #[cfg(target_os = "windows")]
        {
            const CREATE_NO_WINDOW: u32 = 0x08000000;
            const BELOW_NORMAL_PRIORITY_CLASS: u32 = 0x00004000;

            command.creation_flags(CREATE_NO_WINDOW | BELOW_NORMAL_PRIORITY_CLASS);
        }

        let mut child = command
            .spawn()
            .with_context(|| format!("Failed to spawn llama-helper at {:?}", self.helper_binary_path))?;

        let stdin = child.stdin.take().ok_or_else(|| anyhow!("Failed to get stdin"))?;
        let stdout = child.stdout.take().ok_or_else(|| anyhow!("Failed to get stdout"))?;

        // Store handles
        {
            let mut child_lock = self.child_process.lock().await;
            *child_lock = Some(child);
        }

        {
            let mut stdin_lock = self.stdin_writer.lock().await;
            *stdin_lock = Some(stdin);
        }

        {
            let mut stdout_lock = self.stdout_reader.lock().await;
            *stdout_lock = Some(BufReader::new(stdout));
        }

View on GitHub (pinned to 0281737d87)

Solutions

Confirm the Command builder sets .stdin(Stdio::piped()).stdout(Stdio::piped()) before .spawn()
If seen at runtime with stock code, capture the tokio version in use and report it - the piped handle should always be present

Defensive patterns

Strategy: try-catch

Try / catch

let stdin = match child.stdin.take() {
    Some(s) => s,
    None => return Err(anyhow!("spawn misconfigured: stdin must be Stdio::piped() (bug in spawn setup"))),
};

Prevention

Keep .stdin(Stdio::piped()).stdout(Stdio::piped()) adjacent to .spawn() so refactors cannot drop them
Add a unit test asserting the Command builder configures piped stdio before spawn

When it happens

Trigger: A regression or fork that removes .stdin(Stdio::piped()) from the Command builder in spawn(); otherwise not reproducible at runtime because the piped stdio is always requested.

Common situations: Refactoring of the spawn() method; custom builds that change Stdio wiring for logging redirection.

Related errors

AI-assisted analysis of Zackriya-Solutions/meetily@0281737d87 (2026-08-16). Data as JSON: /api/errors/43b010b817abd3e3. Report an issue: GitHub.