vboxsf error when passing owner,group and mount options parameters - vagrant

Question

Vagrant Version 1.6.3
Virtual Box 4.3.12
VBoxGuestAdditions-4.3.2
Host OS -> Windows 8
Guest OS -> CentOS 6.5
Vagrant synced_folder works fine when this is the content of Vagrentfile
config.vm.synced_folder ".", "/vagrant", disabled: true
config.vm.synced_folder ".", "/var/www"
But I am unable to change the permissions of files or directories in synced_folder (/var/www).
https://github.com/mitchellh/vagrant/issues/897
To solve this problem I made following changes in Vagrentfile
https://serverfault.com/questions/398414/vagrant-set-default-share-permissions
config.vm.synced_folder ".", "/vagrant", disabled: true
config.vm.synced_folder ".", "/var/www",
:owner=> 'shiva',
:group=> 'shiva',
:mount_options=> ['dmode=>777', 'fmode=>666']
(where 'shiva' is the user which I created, I deleted the default user 'vagrant')
Now the problem is when I try to do vagrant up ,it shows this error
==> default: Clearing any previously set forwarded ports...
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
default: Adapter 1: nat
==> default: Forwarding ports...
default: 22 => 2222 (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
default: SSH address: 127.0.0.1:2222
default: SSH username: shiva
default: SSH auth method: password
default: Warning: Connection timeout. Retrying...
default: Warning: Connection timeout. Retrying...
default: Warning: Connection timeout. Retrying...
default: Warning: Connection timeout. Retrying...
default: Warning: Remote connection disconnect. Retrying...
==> default: Machine booted and ready!
==> default: Checking for guest additions in VM...
==> default: Mounting shared folders...
default: /var/www => C:/Users/Shiva/CentOSDevEnv_v1_1
Failed to mount folders in Linux guest. This is usually because
the "vboxsf" file system is not available. Please verify that
the guest additions are properly installed in the guest and
can work properly. The command attempted was:
mount -t vboxsf -o uid=`id -u shiva`,gid=`getent group shiva | cut -d: -
f3`,dmode=>777,fmode=>666 var_www /var/www
mount -t vboxsf -o uid=`id -u shiva`,gid=`id -g shiva`,dmode=>777,fmode=
>666 var_www /var/www
I already go through this link
https://github.com/mitchellh/vagrant/issues/3341
I don't know ruby syntax (Vagrantfile syntax).
I am really stuck here, please help.

Answer 1

The error was in my Vagrantfile syntax, my bad :(
This is the correct syntax
:mount_options=> ['dmode=777', 'fmode=666']
But it would be more helpful if vagrant can show the correct error information , something like
"Error in Vagrantfile syntax"
instead of
"This is usually because the "vboxsf" file system is not available. Please verify that
the guest additions are properly installed in the guest and can work properly."