Puppet cannot be `bundle install`'d on Windows due to too strict a version requirement on FFI (of ~> 1.9.25). FFI did not add Window gems for Ruby 2.6 support until FFI 1.10.0.
Change the requirement accordingly.
We're blocked until we release a new ruby facter gem. Filed as FACT-1930.
Merged to master in https://github.com/puppetlabs/puppet/commit/ff0c67ea5aaf1fd76a3474c0d55d3e546e53c3d3