Traceback (most recent call last):
  File "/Users/seanwang/Documents/work/Dev/xUnique/xUnique.py", line 486, in <module>
    main(sys_argv)
  File "/Users/seanwang/Documents/work/Dev/xUnique/xUnique.py", line 468, in main
    xunique.sort_pbxproj(options.sort_pbx_fn_bool)
  File "/Users/seanwang/Documents/work/Dev/xUnique/xUnique.py", line 302, in sort_pbxproj
    lines.sort(key=lambda file_str: pbx_key_ptn.search(file_str).group(1))
  File "/Users/seanwang/Documents/work/Dev/xUnique/xUnique.py", line 302, in <lambda>
    lines.sort(key=lambda file_str: pbx_key_ptn.search(file_str).group(1))
AttributeError: 'NoneType' object has no attribute 'group'