File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/gui/qt/main_window.py", line 1613, in do_pay
    self.do_pay_invoice(self.pending_invoice)
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/gui/qt/main_window.py", line 1627, in do_pay_invoice
    self.pay_onchain_dialog(self.get_coins(), invoice.outputs)
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/gui/qt/main_window.py", line 1668, in pay_onchain_dialog
    if not d.have_enough_funds_assuming_zero_fees():
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/gui/qt/confirm_tx_dialog.py", line 116, in have_enough_funds_assuming_zero_fees
    tx = self.make_tx(0)
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/gui/qt/main_window.py", line 1657, in <lambda>
    is_sweep=is_sweep)
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/wallet.py", line 1253, in make_unsigned_transaction
    dust_threshold=self.dust_threshold())
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/coinchooser.py", line 332, in make_tx
    self.penalty_func(base_tx, tx_from_buckets=tx_from_buckets))
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/coinchooser.py", line 427, in choose_buckets
    scored_candidates = [penalty_func(cand) for cand in candidates]
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/coinchooser.py", line 427, in <listcomp>
    scored_candidates = [penalty_func(cand) for cand in candidates]
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/coinchooser.py", line 456, in penalty
    tx, change_outputs = tx_from_buckets(buckets)
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/coinchooser.py", line 321, in tx_from_buckets
    base_weight=base_weight)
  File "/tmp/.mount_electrv3b24e/usr/lib/python3.7/site-packages/electrum/coinchooser.py", line 235, in _construct_tx_from_selected_buckets
    change_addrs = [tx.inputs()[0].address]