Why is DUB not passing dll.def file to linker

[Igor via Digitalmars-d-learn]

On Saturday, 20 May 2017 at 21:36:42 UTC, Mike Parker wrote:
> On Saturday, 20 May 2017 at 20:26:29 UTC, Igor wrote:
>
>> So my question is if the fix is so simple what are the reasons 
>> it isn't implemented? Am I missing something?
>
> I don't know, but you could always submit a PR or an 
> enhancement request.

Actually, it turned out since 32bit def file needs additional 
settings in it compared to 64bit version it is handy to be able 
to have separate def files and use:

"sourceFiles-windows-x86_64" : ["dll64.def"],
"sourceFiles-windows-x86" : ["dll32.def"],

to only pass appropriate one.

Now since dll project can't be built as a dependency I added this 
to my main project dub.json:

"preBuildCommands": ["cd game & dub build"],

If I now run dub build in main project both projects compile and 
work together, but if I run dub build -ax86_64 only main project 
is built as 64bit while dll project is still being built as 
32bit. Does anyone have a suggestion how can I make this work for 
both architectures?