On an (X)ubuntu host, NFS is not supported

[clebio]

In the Vagrantfile, the line for the synced folder:

    if OS.unix?
      pykcdotdev.vm.synced_folder "./",  "/vagrant/", type: "nfs"

causes the following issue:

Bringing machine 'pykcdotdev' up with 'virtualbox' provider...
==> pykcdotdev: Importing base box 'debian/jessie64'...
==> pykcdotdev: Matching MAC address for NAT networking...
==> pykcdotdev: Checking if box 'debian/jessie64' is up to date...
==> pykcdotdev: Setting the name of the VM: pykcdotdev
It appears your machine doesn't support NFS, or there is not an
adapter to enable NFS on this machine for Vagrant. Please verify
that`nfsd` is installed on your machine, and try again. If you're
on Windows, NFS isn't supported. If the problem persists, please
contact Vagrant support.

Just removing the type specification from that command resolves this, I believe.

[clebio]

Adding the following prior to OS.unix? works for me:

    if OS.linux?
      pykcdotdev.vm.synced_folder "./",  "/vagrant/"

But is all that OS testing necessary? I've never had to use such a construct in a Vagrantfile.