old_contents: import sys
  if sys.version_info >= (3,):
      import builtins
      if not hasattr(builtins, "WindowsError"):
          class WindowsError(Exception):
              pass
      else:
          WindowsError = builtins.WindowsError
  else:
      import __builtin__
      if not hasattr(__builtin__, "WindowsError"):
          class WindowsError(Exception):
              pass
      else:
          WindowsError = __builtin__.WindowsError
  
  class YakuError(Exception):
      pass
  
  class TaskRunFailure(YakuError):
      def __init__(self, cmd, explain=None):
          self.cmd = cmd
          self.explain = explain
  
      def __str__(self):
          ret = "cmd %s failed: \n\n%s" % (" ".join(self.cmd), self.explain)
          return ret.encode("utf-8")
  
  class UnknownTask(YakuError):
      pass
  
  class ToolNotFound(YakuError):
      pass
  
new_contents: import sys
  if sys.version_info >= (3,):
      import builtins
      if not hasattr(builtins, "WindowsError"):
          class WindowsError(Exception):
              pass
      else:
          WindowsError = builtins.WindowsError
  else:
      import __builtin__
      if not hasattr(__builtin__, "WindowsError"):
          class WindowsError(Exception):
              pass
      else:
          WindowsError = __builtin__.WindowsError
  
  class YakuError(Exception):
      pass
  
  class TaskRunFailure(YakuError):
      def __init__(self, cmd, explain=None):
          self.cmd = cmd
          self.explain = explain
  
      def __str__(self):
          ret = "cmd %s failed: \n\n%s" % (" ".join(self.cmd), self.explain)
          if sys.version_info < (3,):
              return ret.encode("utf-8")
          else:
              return ret
  
  class UnknownTask(YakuError):
      pass
  
  class ToolNotFound(YakuError):
      pass
  
subject: fix encoding issue on python 3.