github.com/containers/common/pkg/config
is a configuration related package. When used, I could print the expected:
11:54 $ bin/gggc common Hello containers/common Default containers configuration: /usr/share/containers/containers.conf config.Path(): /home/ggrzybek/.config/containers/containers.conf 11:54 $ sudo bin/gggc common Hello containers/common Default containers configuration: /usr/share/containers/containers.conf config.Path(): /etc/containers/containers.conf