The clang-build on Linux (mbi046) fails with:

/dartclient/MITK/Modules/USUI/Qmitk/QmitkUSAbstractCustomWidget.h:116:76: error: no type named 'ModuleContext' in namespace 'us'

us::ServiceRegistration<QmitkUSAbstractCustomWidget> RegisterService(us::ModuleContext* context);
             ~~~~^

which can be easily solved by adding the usModuleContext.h include to the file.