I managed to get it working, uninstalling Avast Mac Security completely, and making some tweaks to the following in the mariadb
role, based off the MariaDB install wizard:
/trellis/roles/mariadb/defaults/main.yml
mariadb_keyserver_fingerprint: "0xF1656F24C74CD1D8"
mariadb_mirror: sfo1.mirrors.digitalocean.com
mariadb_version: "10.1"
mariadb_dist: xenial
/trellis/roles/mariadb/tasks/main.yml
- name: Add MariaDB MySQL apt-key
apt_key:
keyserver: hkp://keyserver.ubuntu.com:80
id: "{{ mariadb_keyserver_fingerprint }}"
state: present
- name: Add MariaDB MySQL deb and deb-src
apt_repository:
repo: "deb [arch=amd64,i386,ppc64el] http://{{ mariadb_mirror }}/mariadb/repo/{{ mariadb_version }}/ubuntu {{ mariadb_dist | default(ansible_distribution_release) }} main"
state: present