Fail loud on missing balance

update_stop_loss_asset_amount fails loud instead of crashing silently deep in the engine thread

Id: a89d2f74-2078-411c-bf32-a36a33cfcec2 Type: incident Status: active Evidence: confirmed Source: commit 862a96b, PR #63

Found while reproducing a SPOT-exchange crash that didn’t happen under isolated_margin — the same underlying bugs were present there too, just hidden. Root causes found and fixed together:

• UBRA’s get_open_orders actually returns a list, but Cython’s strict typing enforced Optional[dict]

• aggTrade price arrives as a str, crashing under Cython’s strict float typing

• keep_threshold="" slipped past an is not None gate

The key behavioral fix: update_stop_loss_asset_amount now fails loud (fires callback_error/email/Telegram notifications, then stop_manager() and sys.exit(1)) instead of letting total, free = None unpack with a bare TypeError deep in the engine thread — which previously let the stream keep running silently after the crash.

Rejected alternative (implicit — the bug being fixed): letting the TypeError propagate unhandled. That’s what was happening before; the fix isn’t “catch and continue,” it’s “catch, notify loudly through every configured channel, then stop the engine” — same fail-loud pattern already used elsewhere in this file for symbol_info is None (see manager.py ~line 1097).

Reason: a silently-dead engine thread that still looks alive is worse than a crashed one that says so — the whole point of a trailing stop loss is that it’s watching the market; a silent partial failure means it stops protecting a position without anyone knowing.