Vagrant synced folder not updating

Vagrant has a problem with synced folders when using the VirtualBox provider (actually it is a VirtualBox problem).

Connected to the sendfile command means this problem affects web servers running on the guest OS.

To fix it you can either deactivate sendfile if your web server supports this or, in my case using Erlang’s Cowboy, use the VMware provider instead.

If switching to use VMware remember to add the provider flag when bringing up a box vagrant up --provider=vmware_fusion.