The output is a string "0" but your condition uses a bare 0 which is
interpreted as a Boolean false.
But why use a shell workaround, if there is package_facts:
https://docs.ansible.com/ansible/latest/collections/ansible/builtin/package_facts_module.html
Ideally AWS would provide apt repositories
I'm trying to only run a task if the previous task returned a 0 stdout.
- name: Check if efs-utils is already installed
ansible.builtin.shell: dpkg -l | grep efs-utils | wc -l
register: is_installed
ignore_errors: "{{ ansible_check_mode }}"
when: efs_id != "" and not ansible_check_mode
- name: De
