fix(cli): preserve empty failure diagnostics

src/together/lib/cli/_track_cli.py

@@ -275,9 +275,12 @@ def format_cli_error_for_telemetry(exc: BaseException, *, command: str = "") ->
             return sanitize_cli_error_message(msg)
 
     if isinstance(exc, CycloptsError):
-        return sanitize_cli_error_message(_stringify_cyclopts_error(exc))
+        message = _stringify_cyclopts_error(exc)
+    else:
+        message = str(exc)
 
-    return sanitize_cli_error_message(str(exc))
+    sanitized = sanitize_cli_error_message(message)
+    return sanitized or type(exc).__name__
 
 
 def _env_telemetry_disabled() -> bool:

tests/unit/test_cli_telemetry.py

@@ -196,6 +196,17 @@ def test_format_cyclopts_error_omits_install_path() -> None:
     assert err.verbose is True
 
 
+def test_format_empty_cyclopts_error_uses_exception_type() -> None:
+    from cyclopts.exceptions import CycloptsError
+
+    assert format_cli_error_for_telemetry(CycloptsError()) == "CycloptsError"
+
+
+@pytest.mark.parametrize("error", [RuntimeError(), RuntimeError(" \n")])
+def test_format_empty_error_uses_exception_type(error: RuntimeError) -> None:
+    assert format_cli_error_for_telemetry(error) == "RuntimeError"
+
+
 def test_telemetry_env_opt_out_only_explicit_values(monkeypatch: pytest.MonkeyPatch) -> None:
     monkeypatch.delenv("TOGETHER_TELEMETRY_DISABLED", raising=False)
     assert is_tracking_enabled() is True