Playbook runs fine but debug msg module throws undefined variable error.
---
- hosts: labservers
 become: yes
 tasks:
- name: restart httpd
 service:
     name: httpd
     state: restarted
 notify:
     - cmds
 handlers:
- name: change file details
replace:
    path: /etc/httpd/conf/magic
    regexp: 'its is nothing'
    replace: '100 notes ashes'
register: httpd_data
- name: commands out
debug:
    msg: "{{httpd_data}}"
listen: "cmds"
				
                        
Solved by calling both the tasks in handlers using listen.