This answers the part mentioned in the new loader-debian implementation diff:
> About debian lister, in any case:
> - We'll need to adapt slightly the lister to pass solely the origin url and
> not the origin dict
Related D2135
Note: In any case, that can wait after the pile of swh-storage tests
refactoring diff (D 2090-2096 ; D 2117...2119) but also after landing the new
debian loader (if it does ;)