The source project of this merge request has been removed.
Set Dir::Etc::SourceParts empty to avoid using host sources.list.d
If there are any non-default entries in /etc/apt/sources.list.d on the host, then the package-helpers may fail if they can't be retrieved without key issues etc.
This patch sets Dir::Etc::SourceParts "" in the custom apt.conf used in the package helper make-xxxx so there nothing non-default will be picked up from the host /etc/apt/sources.list.d