[Interest] Licensing questions when using shared Qt-library on iOS

[Trillmann, Jens]

Hi,

I'm currently trying to link our app on iOS dynamically against Qt. From 
the technical standpoint everything seems to be working, but I have a 
problem with the licensing.

I would like to conform to the LGPL license, meaning that I want to link 
against all Qt parts dynamically, but I have to link the iOS 
platformplugin statically because qioseventdispatcher.mm defines a 
custom program entry point (and does some voodoo with setjmp/longjmp). I 
currently also have to link statically against some other modules 
(Qt5GraphicsSupport, Qt5FontDatabaseSupport, Qt5ClipboardSupport), but 
the platform plugin is the most crucial part. qioseventdispatcher.mm and 
every other file in the platformplugin is LGPL licensed. From my 
understanding I would violate the LGPL license if I would try to 
distribute the app in this form, because a user could not easily swap 
the provided Qt-library with his own. The app itself is under the 
non-compatible EUPL.

Is there a way to build the iOS platformplugin dynamically? There has 
been some interest in building shared libs for iOS in the past, is there 
maybe already a strategy to be LGPL compliant? On Windows there exists 
qtbase/src/winmain, where the program entry point is isolated into 
BSD-licensed source files. Maybe something similiar could be possible?

best regards,
Jens Trillmann