UnicodeDecodeError in setup_environment when installation prefix path contains non-ASCII characters

[Vdragon]

Bug Reproduce Instructions

$ mkdir 中文
$ git clone <git-cola-repo-dir> 中文
$ 中文/bin/git-cola

Traceback

Traceback (most recent call last):
  File "中文/bin/git-cola", line 57, in <module>
    sys.exit(main())
  File "中文/cola/main.py", line 37, in main
    return args.func(args)
  File "中文/cola/main.py", line 285, in cmd_cola
    context = application_init(args)
  File "中文/cola/app.py", line 229, in application_init
    setup_environment()
  File "中文/cola/app.py", line 67, in setup_environment
    path = os.pathsep.join(path_entries)
UnicodeDecodeError: 'ascii' codec can't decode byte <stripped> in position <stripped>: ordinal not in range(128)

Reporter's Environment

Git Cola

commit 9c10678

Operating System

Ubuntu 16.04 AMD64

Locale

LANG=zh_TW.UTF-8
LANGUAGE=zh_TW:zh_HK:zh
LC_CTYPE="zh_TW.UTF-8"
LC_NUMERIC="zh_TW.UTF-8"
LC_TIME="zh_TW.UTF-8"
LC_COLLATE="zh_TW.UTF-8"
LC_MONETARY="zh_TW.UTF-8"
LC_MESSAGES="zh_TW.UTF-8"
LC_PAPER="zh_TW.UTF-8"
LC_NAME="zh_TW.UTF-8"
LC_ADDRESS="zh_TW.UTF-8"
LC_TELEPHONE="zh_TW.UTF-8"
LC_MEASUREMENT="zh_TW.UTF-8"
LC_IDENTIFICATION="zh_TW.UTF-8"
LC_ALL=