denoland/deno · error

could not find '{backend}' .app bundle under {} (set via {})

Error message

could not find '{backend}' .app bundle under {} (set via {})

What it means

Error "could not find '{backend}' .app bundle under {} (set via {})" thrown in denoland/deno.

Source

Thrown at cli/tools/desktop.rs:2104

    let dir = self.ensure_downloaded(backend, target).await?;
    locate_backend_binary(&dir, backend, target).ok_or_else(|| {
      deno_core::anyhow::anyhow!(
        "could not find '{backend}' backend binary inside {}",
        dir.display()
      )
    })
  }

  /// Locate the LAUFEY `.app` bundle for `backend` on a macOS `target`.
  async fn find_app_bundle(
    &self,
    backend: &str,
    target: &str,
  ) -> Result<PathBuf, AnyError> {
    if let Some(dev_dir) = laufey_dev_dir() {
      return locate_dev_app_bundle(&dev_dir, backend).ok_or_else(|| {
        deno_core::anyhow::anyhow!(
          "could not find '{backend}' .app bundle under {} (set via {})",
          dev_dir.display(),
          LAUFEY_DEV_DIR_ENV
        )
      });
    }

    let dir = self.ensure_downloaded(backend, target).await?;
    locate_app_bundle(&dir, backend).ok_or_else(|| {
      deno_core::anyhow::anyhow!(
        "could not find '{backend}' .app bundle inside {} (backend may not ship as an app for target '{target}')",
        dir.display()
      )
    })
  }

  /// Directory containing the backend binary and its support files (used on
  /// Windows / Linux where support files sit alongside the binary).

View on GitHub (pinned to 89f33cbef2)

When it happens

Trigger: Thrown at cli/tools/desktop.rs:2104 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/fd856298f3b2c7d6. Report an issue: GitHub.