File "./electrum/util.py", line 882, in run_with_except_hook
    run_original(*args2, **kwargs2)
  File "./electrum/network.py", line 1085, in run
    self.wait_on_sockets()
  File "./electrum/network.py", line 1067, in wait_on_sockets
    self.process_responses(interface)
  File "./electrum/network.py", line 719, in process_responses
    self.process_response(interface, response, callbacks)
  File "./electrum/network.py", line 659, in process_response
    self.on_get_header(interface, response)
  File "./electrum/network.py", line 917, in on_get_header
    interface.blockchain.save_header(header)
  File "./electrum/blockchain.py", line 126, in func_wrapper
    return func(self, *args, **kwargs)
  File "./electrum/blockchain.py", line 282, in save_header
    self.write(data, delta*80)
  File "./electrum/blockchain.py", line 272, in write
    os.fsync(f.fileno())