This looks to be because the netbook image doesn't have /etc/default-release or a preseeded value for the debconf suite, resulting in choose-mirror failing, resulting in source/apt-setup/generators/50mirror.ubuntu failing to write out the default sources.list.
This looks to be because the netbook image doesn't have /etc/default- release or a preseeded value for the debconf suite, resulting in choose-mirror failing, resulting in source/ apt-setup/ generators/ 50mirror. ubuntu failing to write out the default sources.list.