Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 178, in _process_transaction
    lock.wait_for_lock(trans)
  File "/usr/lib/python2.7/dist-packages/aptdaemon/lock.py", line 165, in wait_for_lock
    acquire()
  File "/usr/lib/python2.7/dist-packages/aptdaemon/lock.py", line 127, in acquire
    lock.acquire()
  File "/usr/lib/python2.7/dist-packages/aptdaemon/lock.py", line 72, in acquire
    process = get_locking_process_name(self.path)
  File "/usr/lib/python2.7/dist-packages/aptdaemon/lock.py", line 89, in get_locking_process_name
    with open(lock_path,"r") as fd_lock_read:
IOError: [Errno 2] No such file or directory: '/var/cache/apt/archives/lock'