What causes "打开 DMG 失败：{error}" in BigPizzaV3/CodexPlusPlus?

Confirm /usr/bin/open exists and works: run `open` from a terminal.

打开 DMG 失败：

Error message

打开 DMG 失败：{error}

What it means

On macOS, launch_installer opens the downloaded .dmg via the system 'open' command. If spawning 'open' fails, the io error is mapped to 打开 DMG 失败：{error}. Note that on any non-Windows, non-macOS platform the function instead throws the unrelated '当前平台不支持启动安装包' error.

Solutions

Confirm /usr/bin/open exists and works: run `open` from a terminal.
Verify the .dmg still exists at the reported installer_path; re-download via perform_update if a cleaner removed it.
Open the .dmg manually with Finder or `open <path>` to complete the update.
Retry perform_update — spawn failures from transient resource limits usually clear.
If 'open' is genuinely unavailable, mount the .dmg with hdiutil attach and copy the app manually.

Example fix

// before
let install = perform_update(&release, &dir).await?; // panics flow on 打开 DMG 失败
// after
match perform_update(&release, &dir).await {
    Ok(i) => ..., // i.launched == true on success
    Err(e) if e.to_string().contains("打开 DMG 失败") => {
        eprintln!("auto-open failed: {e}; mount {} with hdiutil/Finder", expected_dmg.display());
    }
    Err(e) => return Err(e),
}

Defensive patterns

Strategy: try-catch

Validate before calling

fn dmg_openable(path: &std::path::Path) -> bool {
    path.is_file()
        && std::process::Command::new("open")
            .arg("--help")
            .output()
            .map(|o| o.status.success())
            .unwrap_or(false)
}

Try / catch

match perform_update(&release, &dir).await {
    Ok(install) => Ok(install),
    Err(e) if e.to_string().contains("打开 DMG 失败") => {
        eprintln!("auto-open failed: {e}; mount {} via Finder or `hdiutil attach`", expected_dmg.display());
        Err(e)
    }
    Err(e) => Err(e),
}

Prevention

Don't remove the download directory between download and launch — cleaners can race the updater.
Keep the dmg path intact and verify it exists before invoking the update flow.
On macOS ensure the process environment can spawn /usr/bin/open (avoid broken PATH in launchd contexts).
Provide the dmg path in the error UI so users can finish the install manually.

When it happens

Trigger: Calling perform_update on macOS when: the 'open' binary is missing from PATH (rare, broken/minimal environment), spawn fails due to resource limits, or the downloaded path was removed before launch. The .dmg file itself opening-then-failing in Finder is NOT this error — only the spawn failure is.

Common situations: Running the app in a sandboxed/odd environment without /usr/bin/open; installer file deleted by a cleaner between download and launch; disk-full or fork-limit conditions preventing process creation.

Related errors

AI-assisted analysis of BigPizzaV3/CodexPlusPlus@b1ed92e5e4 (2026-09-19). Data as JSON: /api/errors/5603e8e0eb0abdd5. Report an issue: GitHub.

Appendix: source

Thrown at crates/codex-plus-core/src/update.rs:427

pub fn launch_installer(path: &Path) -> anyhow::Result<()> {
    #[cfg(windows)]
    {
        use std::os::windows::process::CommandExt;
        std::process::Command::new(path)
            .creation_flags(crate::windows_integration::CREATE_NO_WINDOW)
            .spawn()
            .map(|_| ())
            .map_err(|error| anyhow::anyhow!("启动安装包失败：{error}"))
    }

    #[cfg(target_os = "macos")]
    {
        std::process::Command::new("open")
            .arg(path)
            .spawn()
            .map(|_| ())
            .map_err(|error| anyhow::anyhow!("打开 DMG 失败：{error}"))
    }

    #[cfg(all(not(windows), not(target_os = "macos")))]
    {
        let _ = path;
        anyhow::bail!("当前平台不支持启动安装包")
    }
}

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