Ansible bug with parameterized roles

Output.txt

PLAY [localhost] ***************************************************************************************************************************

TASK [Gathering Facts] *********************************************************************************************************************
ok: [localhost]

TASK [Running for first] *******************************************************************************************************************

TASK [bar : debug] *************************************************************************************************************************
ok: [localhost] => {
    "msg": "var_bar is second"
}

TASK [Running for second] ******************************************************************************************************************

TASK [bar : debug] *************************************************************************************************************************
ok: [localhost] => {
    "msg": "var_bar is second"
}

PLAY RECAP *********************************************************************************************************************************
localhost                  : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

playbook.yaml

---
- hosts: localhost
  connection: local
  roles:
    - role: foo
      vars:
        var_foo: 'first'
    - role: foo
      vars:
        var_foo: 'second'

roles-bar-tasks-main.yaml

---
# tasks file for bar
- debug:
    msg: "var_bar is {{ var_bar }}"

roles-foo-tasks-main.yaml

---
# tasks file for foo
- name: "Running for {{ var_foo }}"
  include_role:
    name: bar
  vars:
    var_bar: "{{ var_foo }}"

Notice the task names for each parameterized role inclusion have the corect value for var_foo.

However, during the execution of the include_role, var_bar is set for both the first and second invocation to the value of var_foo in tthe last instance of the parameterized role.