[Development] Enabling private features for separate modules

[Alexander Volkov]

19.06.2017 13:59, Dominik Holland пишет:
>> $ qmake -- -system-ffmpeg
>> ***Unknown option -system-ffmpeg
> I think it needs to be:
>
> qmake -- --enable-system-ffmpeg
>
> if you want to add your own options you can also add a "commandline"
> section to configure.json
It also doesn't work. Somehow this way of passing extra arguments with 
'--' doesn't work in release builds.
I tested it in my developer build and it works.
Also I found that it was introduced by 
https://codereview.qt-project.org/#/c/159056/
and there is another way of passing extra arguments with QMAKE_EXTRA_ARGS:
qmake QMAKE_EXTRA_ARGS+="-system-ffmpeg" works.