With latest Ansible we had an issue starting up / provisioning vagrant properly. It would not provision properly stating there was an attribute called options missing.

Attribute Options Errors

Got the following error doing a

ansible reload --provision

ERROR! Unexpected Exception, this is probably a bug: 'PlaybookCLI' object has no attribute 'options'

Suggestion at Roots Discourse was to downgrade Ansible to < 2.8 using

sudo pip uninstall ansible 
sudo pip install ansible==2.7

And although that is again not an ideal solution it is the solution if you do not want to upgrade Trellis and or work with Python 3 as discussed at this blog post.