File "electrum\gui\qt\confirm_tx_dialog.py", line 66, in timer_actions
  File "electrum\gui\qt\confirm_tx_dialog.py", line 86, in update_tx
  File "electrum\gui\qt\main_window.py", line 1657, in <lambda>
  File "electrum\wallet.py", line 1253, in make_unsigned_transaction
  File "electrum\coinchooser.py", line 332, in make_tx
  File "electrum\coinchooser.py", line 427, in choose_buckets
  File "electrum\coinchooser.py", line 427, in <listcomp>
  File "electrum\coinchooser.py", line 456, in penalty
  File "electrum\coinchooser.py", line 321, in tx_from_buckets
  File "electrum\coinchooser.py", line 235, in _construct_tx_from_selected_buckets