with FEATURES=test, soprano needs qt-test it seems: CMake Error: The following variables are used in this project, but they are set to NOTFOUND. Please set them or make sure they are set and tested correctly in the CMake files: QT_QTTEST_LIBRARY (ADVANCED) linked by target "asyncmodeltest" in directory /var/tmp/portage/dev-libs/soprano-2.4.3/work/soprano-2.4.3/test linked by target "datetimetest" in directory /var/tmp/portage/dev-libs/soprano-2.4.3/work/soprano-2.4.3/test linked by target "errortest" in directory /var/tmp/portage/dev-libs/soprano-2.4.3/work/soprano-2.4.3/test
Fixed in the kde overlay, please test.
In portage. Thanks for all involved!