As of version 3.0.0 tldextract requires filelock during runtime. [0] In nixpkgs tldextract was bumped from version 2.2.3 to 3.1.0 in5b2d82451fwithout actually updating the dependencies breaking packages such as qutebrowser. This fix is part of this series to verify that bumping qt5 to 5.15.2 actually fixes the crash caused by WebRTC [1]. [0]2eba0e5ebd[1] https://bugreports.qt.io/browse/QTBUG-86752