Mongodb3 Chef >> Metachef Error

gistfile1.txt

       Recipe Compile Error in /tmp/kitchen/cache/cookbooks/metachef/attributes/default.rb
       ================================================================================
       
       TypeError
       ---------
       no implicit conversion of String into Integer
       
       Cookbook Trace:
       ---------------
         /tmp/kitchen/cache/cookbooks/metachef/attributes/default.rb:9:in `[]'
         /tmp/kitchen/cache/cookbooks/metachef/attributes/default.rb:9:in `from_file'
       
       
       ----------------------
       /tmp/kitchen/cache/cookbooks/metachef/attributes/default.rb:
       
         2:  default[:metachef][:conf_dir] = '/etc/metachef'
         3:  default[:metachef][:log_dir]  = '/var/log/metachef'
         4:  default[:metachef][:home_dir] = '/etc/metachef'
         5:  
         6:  default[:metachef][:user]     = 'root'
         7:  
         8:  # Request user account properties here.
         9>> default[:users]['root'][:primary_group] = value_for_platform(
        10:    "openbsd"   => { "default" => "wheel" },
       
        12:    "mac_os_x"  => { "default" => "wheel" },
        13:    "default"   => "root"
        14:  )
        15:  
        16:  default[:announces] ||= Mash.new
        17:  
        18:  default[:discovers] ||= Mash.new
       
       
       Running handlers:
       
       
       [2016-02-01T16:29:22+00:00] ERROR: Exception handlers complete

how did you fix this issue?