Zackriya-Solutions/meetily · info

Failed to open stdin

Error message

Failed to open stdin

What it means

Child::stdin is Option<ChildStdin>; take() returns None only when the child was spawned without Stdio::piped() stdin. The builder sets .stdin(Stdio::piped()) a few lines above, so this expect is a structural invariant that can only fire if a refactor removes the piped() call while keeping the take().

Source

Thrown at frontend/src-tauri/src/audio/encode.rs:76

        ])
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped());

    // Hide console window on Windows to prevent CMD popup during recording
    #[cfg(target_os = "windows")]
    {
        use std::os::windows::process::CommandExt;
        const CREATE_NO_WINDOW: u32 = 0x08000000;
        command.creation_flags(CREATE_NO_WINDOW);
    }

    debug!("FFmpeg command: {:?}", command);

    #[allow(clippy::zombie_processes)]
    let mut ffmpeg = command.spawn().expect("Failed to spawn FFmpeg process");
    debug!("FFmpeg process spawned");
    let mut stdin = ffmpeg.stdin.take().expect("Failed to open stdin");

    stdin.write_all(data)?;

    debug!("Dropping stdin");
    drop(stdin);
    debug!("Waiting for FFmpeg process to exit");
    let output = ffmpeg.wait_with_output().unwrap();
    let status = output.status;
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);

    debug!("FFmpeg process exited with status: {}", status);
    debug!("FFmpeg stdout: {}", stdout);
    debug!("FFmpeg stderr: {}", stderr);

    if !status.success() {
        error!("FFmpeg process failed with status: {}", status);
        error!("FFmpeg stderr: {}", stderr);

View on GitHub (pinned to 0281737d87)

Solutions

1. Keep the Stdio::piped() call adjacent to spawn() in the same function
2. Replace expect with an anyhow error ('FFmpeg stdin was not piped') so future refactors fail gracefully
3. Add a unit test that runs the encoder with a few bytes of silence and asserts success

Example fix

// before
let mut stdin = ffmpeg.stdin.take().expect("Failed to open stdin");

// after
let mut stdin = ffmpeg.stdin.take().context("FFmpeg stdin was not piped")?;

// keep the invariant testable
#[test]
fn encode_pipes_stdin() {
    // builds the same command; asserts stdin is piped
    assert!(command_stdin_is_piped(build_command()));
}

let Some(mut stdin) = ffmpeg.stdin.take() else {
    return Err(anyhow::anyhow!("FFmpeg stdin was not piped"));
};

When it happens

Trigger: Refactoring encode_single_audio so .stdin(Stdio::piped()) is dropped or gated behind a flag; moving command construction into a shared helper that forgets to pipe stdin while the caller still takes it.

Common situations: Almost never seen in shipped builds; a maintenance hazard when the command builder is generalized for other ffmpeg invocations.

Related errors

• Failed to create valid path
• Buffer should always be available
• Failed to spawn FFmpeg process
• FFmpeg not found. FFmpeg is required to decode .{} files. It
• Failed to create temporary WAV file: {}

AI-assisted analysis of Zackriya-Solutions/meetily@0281737d87 (2026-08-16). Data as JSON: /api/errors/6b800726f1627e20. Report an issue: GitHub.