Using Ansible hosts raises `--limit` does not match any hosts - vagrant

Question

My Vagrantfile looks like:
Vagrant.configure("2") do |config|
config.vm.box = "vag-box"
config.vm.box_url = "boxes/base.box"
config.vm.network :private_network, ip: "192.168.100.100"
config.vm.provision :setup, type: :ansible_local do |ansible|
ansible.playbook = "playbook.yml"
ansible.provisioning_path = "/vagrant"
ansible.inventory_path = "/vagrant/hosts"
end
end
My playbook file looks like:
---
- name: Setup system
hosts: localhost
become: true
become_user: root
roles:
- { role: role1 }
- { role: role2 }
My hosts file looks like:
[localhost]
localhost # 192.168.100.100
During ansible execution I get the following error:
ERROR! Specified --limit does not match any hosts

Answer 1

First: "localhost" is a name that is assigned to the 127.0.0.1 address by convention. This refers to the loopback address of the local machine. I don't think this is what you are trying to use it for, based on the comment in your hosts file.
Second: The Ansible provisioner in Vagrant usually creates a custom inventory file, with the required contents to provision the Vagrant box. For example:
# Generated by Vagrant
myvagrantbox ansible_ssh_host=127.0.0.1 ansible_ssh_port=2222 ansible_ssh_user='vagrant' ansible_ssh_private_key_file='/home/sage/ansible/vagrant/myvagrantbox/.vagrant/machines/myvagrantbox/virtualbox/private_key'
As you are overriding the inventory file, you will need to specify a similar line for the hostname of your vagrant box.
If you omit the ansible.inventory_path = "/vagrant/hosts" line from your config, it should JustWork(tm). You might also wish to specify config.vm.hostname = "myvagrantboxname" in your configuration, so you know what hostname will be used.
See the Using Vagrant and Ansible and the Vagrant -- Ansible Provisioner documentation for more details.