I believe variable resolution in nested add_role is still not working properly. For example if we change the example shown in the ticket above such that instead of the line
b: “{{ a+1 }}”
in ./roles/a/tasks/main.yml where (a is a variable that was passed to the add_role) we had instead
b: “{{a_defaults_var}}”
where a_defaults_var was a variable not passed to the add_role. (It was for example defined in roles/a/defaults/main.yml) then we get a a_defaults_var not defined.