bundle identifier {id:?} must match [A-Za-z0-9.-]+, but cont

Error message

bundle identifier {id:?} must match [A-Za-z0-9.-]+, but contains {c:?}

What it means

Thrown by validate_bundle_identifier when `--identifier` contains a character outside [A-Za-z0-9.-]; the message names the offending character. Beyond Apple's CFBundleIdentifier charset this also blocks shell metacharacters, because the identifier is passed as a `codesign` argument and used as a path component of the CEF helper bundles.

Source

Thrown at cli/tools/desktop.rs:2478

/// a path component of the helper bundles.
fn validate_bundle_identifier(id: &str) -> Result<(), AnyError> {
  if id.is_empty() {
    bail!("bundle identifier is empty");
  }
  if id.len() > 155 {
    // Apple's documented limit for CFBundleIdentifier on receipts is
    // 155 chars; bigger values quietly truncate elsewhere in the
    // toolchain.
    bail!("bundle identifier {id:?} is longer than 155 characters");
  }
  if !id.contains('.') {
    bail!(
      "bundle identifier {id:?} must be in reverse-DNS form (e.g. com.acme.foo)"
    );
  }
  for c in id.chars() {
    if !(c.is_ascii_alphanumeric() || c == '.' || c == '-') {
      bail!(
        "bundle identifier {id:?} must match [A-Za-z0-9.-]+, but contains {c:?}",
      );
    }
  }
  if id.split('.').any(|seg| seg.is_empty()) {
    bail!("bundle identifier {id:?} has an empty segment");
  }
  Ok(())
}

/// Walk every `.app` under `Contents/Frameworks/` and rewrite its
/// `CFBundleIdentifier` so it's a strict suffix of `main_bundle_id`.
///
/// CEF's process model: when the browser process spawns a helper for a
/// child role (gpu, renderer, plugin, …), the helper inspects its own
/// `CFBundleIdentifier` and refuses to attach to a parent whose id
/// doesn't match it as a prefix. laufey's default helper plists ship with
/// `com.example.laufey.helper.*` — which is inconsistent with whatever id

View on GitHub (pinned to f7822238ca)

Solutions

Replace invalid characters: use hyphens instead of underscores (`my-app` not `my_app`) and drop everything that is not a letter, digit, dot, or hyphen.
Transliterate non-ASCII names to plain ASCII (Bäcker -> baeker).
Use the reverse-DNS form of a domain you control rather than pasting a URL.

Example fix

# before
deno desktop --identifier com.acme.my_app main.ts

# after
deno desktop --identifier com.acme.my-app main.ts

Defensive patterns

Strategy: validation

Validate before calling

# bash: enforce the charset
BUNDLE_ID="com.acme.my-app"
[[ "$BUNDLE_ID" =~ ^[A-Za-z0-9.-]+$ ]] || { echo "identifier has invalid characters" >&2; exit 1; }
deno desktop --identifier "$BUNDLE_ID" main.ts

Type guard

// TypeScript
function hasOnlyBundleIdChars(id: string): boolean {
  return /^[A-Za-z0-9.-]+$/.test(id);
}

Prevention

Use hyphens where you would use underscores (my-app, not my_app).
Transliterate non-ASCII product names to ASCII before building the id.
Add a regex lint for the identifier in CI to catch regressions early.

When it happens

Trigger: `--identifier com.acme.my_app` (underscore — the single most common hit), spaces, `://`, quotes, unicode letters (é, ü), or any shell metacharacter in the value.

Common situations: Underscores carried over from npm package names or repo names; copy-pasting a URL (`https://acme.com`) instead of the reverse-DNS form; non-ASCII company/product names pasted verbatim.

Related errors

AI-assisted analysis of denoland/deno@f7822238ca (2026-08-20). Data as JSON: /api/errors/23a9313f19528178. Report an issue: GitHub.