Traceback (most recent call last):
  File "/usr/lib/ubiquity/bin/ubiquity", line 201, in <module>
    main()
  File "/usr/lib/ubiquity/bin/ubiquity", line 161, in main
    os.makedirs('/var/log/installer')
  File "os.py", line 172, in makedirs
    mkdir(name, mode)
OSError: [Errno 17] File exists: '/var/log/installer'