To debug the provisioning step Drupal VM can run the ansible-playbook command in verbose mode if you set the DRUPALVM_DEBUG environment variable.
# verbose mode: ansible-playbook -v
DRUPALVM_DEBUG=1 vagrant provision
DRUPALVM_DEBUG=v vagrant provision
# for even more messages: ansible-playbook -vvv
DRUPALVM_DEBUG=vvv vagrant provision
# for debug mode: ansible-playbook -vvvv
DRUPALVM_DEBUG=vvvv vagrant provisionIn addition to running in verbose mode this also enables deprecation warnings.
For debugging information related to Vagrant see documentation.