could not find '{backend}' backend binary under {} (set via

Error message

could not find '{backend}' backend binary under {} (set via {})

What it means

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

Source

Thrown at cli/tools/desktop.rs:2064

      );
    }

    Ok(dir)
  }

  /// Locate the LAUFEY backend binary for `backend` on `target`.
  ///
  /// Resolution order: `LAUFEY_DEV_DIR` checkout → cached download →
  /// fresh download.
  async fn find_binary(
    &self,
    backend: &str,
    target: &str,
  ) -> Result<PathBuf, AnyError> {
    if let Some(dev_dir) = laufey_dev_dir() {
      let binary =
        locate_dev_backend_binary(&dev_dir, backend).ok_or_else(|| {
          deno_core::anyhow::anyhow!(
            "could not find '{backend}' backend binary under {} (set via {})",
            dev_dir.display(),
            LAUFEY_DEV_DIR_ENV
          )
        })?;
      // Re-sign the dev laufey build so its identifier matches the bundle
      // id — same fix as the download path, applied every launch
      // because a fresh `cargo build` of laufey restores the linker's
      // default `Identifier=laufey`. The harmonize call is idempotent:
      // already-correct binaries are skipped.
      #[cfg(target_os = "macos")]
      if let Some(laufey_app) = laufey_app_for_binary(&binary)
        && let Err(e) = harmonize_laufey_app_identifiers(&laufey_app)
      {
        log::warn!(
          "[desktop] could not re-sign dev laufey backend: {e} \
           (notifications may not work in HMR mode)"
        );

View on GitHub (pinned to 89f33cbef2)

When it happens

Trigger: Thrown at cli/tools/desktop.rs:2064 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/7d0fae28d6ceca60. Report an issue: GitHub.