The documentation (http://doc.qt.io/qt-5/resources.html and https://wiki.qt.io/QtResources) suggests to call Q_INIT_RESOURCE(name) from main to trigger loading of library resources. This works fine for static libraries. For shared libraries however, it generates a linker error (unresolved external symbol).
I have spent a few hours trying to figure out why and I think the reason must be that the generated qInitResources_name() is not exported, i.e. it is not declared using Q_DECL_EXPORT. Therefore it cannot be seen from the application's main function.
If I am right, I suggest that you mention this in the documentation, or even better; modifies the Q_INIT_RESOURCE macro to ensure that the generated function gets exported when generated inside a shared library.
For now, the obvious workaround is to create a separate function in the shared library that uses Q_INIT_RESOURCE, make sure to export this function using Q_DECL_EXPORT and call it from main instead of using Q_INIT_RESOURCE directly.