DUB, link automatically right object for platform and archi

[Basile B. via Digitalmars-d-learn]

On Thursday, 1 September 2016 at 18:01:19 UTC, Basile B. wrote:
> I've converted this section:
> [...]
> to:
>
>
>   "buildSettings" : {
>     "dflags-linux-x86" : ["objects/coff32/beaengine.o"],
>     "dflags-linux-x86_64" : ["objects/coff64/beaengine.o"],
>     "dflags-windows-x86" : ["objects\\omf32\\beaengine.obj"]
>   },
>
>
> Because previously the right config could not be selected when 
> the package was used as dependency. But now the object is not 
> linked in the static library produced by the project.
>
> What's wrong in my description ?

neither dflags, lflags nor sourceFiles work. Strangely enough 
this new section is completely missing in the dub.json obtained 
after the dub fetch.