I tried upgrading to from 1.6 to 1.7 and 1.8 and get the following error. Is it because vagrant 1.7+ requires ruby 2?
/var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/lib/vagrant-wrapper.rb:134:in `match': invalid byte sequence in UTF-8 (ArgumentError)
from /var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/lib/vagrant-wrapper.rb:134:in `match'
from /var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/lib/vagrant-wrapper.rb:134:in `block in find_vagrant'
from /var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/lib/vagrant-wrapper.rb:131:in `each'
from /var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/lib/vagrant-wrapper.rb:131:in `find_vagrant'
from /var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/lib/vagrant-wrapper.rb:153:in `exec_vagrant'
from /var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/lib/vagrant-wrapper.rb:67:in `execute'
from /var/lib/gems/1.9.1/gems/vagrant-wrapper-1.2.1.1/bin/vagrant:12:in `<top (required)>'
from /usr/local/bin/vagrant:23:in `load'
from /usr/local/bin/vagrant:23:in `<main>'