Adding flags to dub build

[Jean-Louis Leroy via Digitalmars-d-learn]

Hi,

I want to add a few flags while building with dub. I tried:
    DFLAGS='-d-version=explain' dub test ...

...but DFLAGS does not seem to be honored. In fact I wouldn't 
mind adding a builtType to my dub.sdl (but then will it be 
inherited by the subpackages) but I don't see how to specify 
flags there either...maybe because it tries to hide variations in 
compiler switches?

J-L