Just log error on invalid order mode settings

piker/ui/_position.py

@@ -208,13 +208,17 @@ class SettingsPane:
         size_unit = alloc.size_unit
 
         # WRITE any settings to current pp's allocator
+        try:
             if key == 'limit':
                     if size_unit == 'currency':
+                        # old = alloc.currency_limit
                         alloc.currency_limit = float(value)
                     else:
+                        # old = alloc.units_limit
                         alloc.units_limit = float(value)
 
             elif key == 'slots':
+                # old = alloc.slots
                 alloc.slots = int(value)
 
             elif key == 'size_unit':
@@ -225,9 +229,12 @@ class SettingsPane:
             elif key != 'account':
                 raise ValueError(f'Unknown setting {key}')
 
-        # READ out settings and update UI
             log.info(f'settings change: {key}: {value}')
 
+        except ValueError:
+            log.error(f'Invalid value for `{key}`: {value}')
+
+        # READ out settings and update UI
         suffix = {'currency': ' $', 'units': ' u'}[size_unit]
         limit = alloc.limit()