afiune/kitchen-vagrant — pull request #5 by btm (2014-12-11 20:22:48+00:00)
Title: Use '--provider FOO' (with a space)

For some reason I'm getting this error:
---- Begin output of vagrant up --no-provision --provider=virtualbox ----
STDOUT:
STDERR: An invalid option was specified. The help for this command
is available below.

All signs point to the correct argument not having an equals sign.