【Vagrant】The 'extra' flag on synced folders is now 'mount_options'の対処法

vagrant up

をした時に以下のエラーが出た。

There are errors in the configuration of this machine. Please fix
the following errors and try again:

vm:
* The 'extra' flag on synced folders is now 'mount_options'

config.vm.share_folderの:extraの部分を:mount_optionsに修正すればOK

config.vm.share_folder("./www", :mount_options => ["dmode=777","fmode=777"])

参考

Vagrant1.3.5ではconfig.vm.synced_folderのパーミッションをmount_optionsで設定する