denoland/deno · error

could not get fetch esbuild binary; download it manually and

Error message

could not get fetch esbuild binary; download it manually and copy it to {}

What it means

deno bundle shells out to esbuild, fetching the pinned esbuild npm package on first use and copying its platform binary into DENO_DIR. This bail (cli/tools/bundle/esbuild.rs:150-155) fires when the registry metadata for the pinned esbuild version carries no dist tarball information (version_info.dist is None), so there is nothing to download - typical of broken mirrors, custom registries lacking the package, or proxied/offline environments. The message names the exact path where the binary is expected so it can be installed manually.

Source

Thrown at cli/tools/bundle/esbuild.rs:151

            "failed to move esbuild binary into place at {}",
            esbuild_path.display()
          )
        });
      }
    }

    if !existed {
      let _ = std::fs::remove_dir_all(&package_folder).inspect_err(|e| {
        log::warn!(
          "failed to remove directory {}: {}",
          package_folder.display(),
          e
        );
      });
    }
    Ok(esbuild_path)
  } else {
    anyhow::bail!(
      "could not get fetch esbuild binary; download it manually and copy it to {}",
      esbuild_path.display()
    );
  }
}

View on GitHub (pinned to 89f33cbef2)

Solutions

1. Check registry connectivity/config: verify the registry URL in npmrc (.npmrc registry=, DENO_ env overrides) and that it serves the esbuild package with dist for the pinned version
2. Retry after fixing network/proxy (the earlier download attempts log 'failed to download esbuild package tarball ...' when the tarball itself fails)
3. Manually install: download the esbuild binary matching the pinned version for your platform, make it executable, and copy it to the exact path printed in the error (under DENO_DIR; find it via 'deno info')
4. Run once from a machine with normal registry access, then copy the cached binary into the same DENO_DIR path on the restricted machine

Example fix

# before: fails with 'could not get fetch esbuild binary; download it manually and copy it to /home/ci/.cache/deno/esbuild-...'
deno bundle src/main.ts out.js
# after: manual install on the restricted host
ESBUILD_PATH=$(deno info | grep 'DENO_DIR' || true)
# take the path from the error message, then:
cp ./tools/esbuild-linux-x64 /home/ci/.cache/deno/esbuild-X_Y_Z/esbuild
chmod +x /home/ci/.cache/deno/esbuild-X_Y_Z/esbuild
deno bundle src/main.ts out.js

# Verify the registry serves the pinned esbuild package with a dist tarball
ESBUILD_VERSION=$(deno --version | head -1)  # or read from the error message
curl -fsS "${NPM_REGISTRY:-https://registry.npmjs.org}/esbuild" \
  | jq -e --arg v "$ESBUILD_VERSION" '.versions[$v].dist.tarball' >/dev/null \
  && echo 'esbuild dist available' || echo 'registry missing esbuild dist - pre-install manually'

# Pre-seed the binary from a mirror, then run the bundle
ERRLOG=$(mktemp)
deno bundle src/main.ts out.js 2>&1 | tee "$ERRLOG" || {
  path=$(sed -n 's/.*copy it to \(.*\)/\1/p' "$ERRLOG")
  [ -n "$path" ] && cp ./vendor/esbuild "$path" && chmod +x "$path" && deno bundle src/main.ts out.js
}

When it happens

Trigger: npm registry metadata reachable but missing the dist field for the pinned esbuild version (misconfigured mirror, allowlist-style proxy, air-gapped Artifactory/Verdaccio feed without esbuild); registry returning truncated metadata; unusual ESBUILD_VERSION pin not present in the mirror.

Common situations: Corporate networks with a private npm registry that doesn't proxy esbuild; offline/air-gapped build agents; registry outages serving degraded metadata; DENO_DIR on read-only or full disk making earlier install steps silently unavailable.

Related errors

• failed to locate output for HTML entry '{}'; {js_entry_name}
• bundling failed
• esbuild produced no JavaScript output
• esbuild exited before the rebuild completed
• The bench function must have a name

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/adb886cfe8f9a162. Report an issue: GitHub.