How to pass -J switch to compiler via DUB?

[Andrey]

On Friday, 30 November 2018 at 11:21:04 UTC, fghost wrote:
> On Friday, 30 November 2018 at 11:05:26 UTC, Andrey wrote:
>> Hi,
>> How to pass -J switch to compiler via DUB?
>> I want to import some text file at compile time:
>>> string data = import("vertex.glsl");
>>
>> In dub.json:
>> "dflags": [
>>     "-J=vertex.glsl"
>> ]
>>
>> The file itself is located on the same level as "dub.json".
>
> The -J switch takes a directory path, not path to the file 
> directly.

Thanks to all.