Commit fe1151218c ("chiaki: cleanup package") replaced mkDerivation
with stdenv mkDerivation, which is wrong for QT5 applications and
results in the following error on start:
qt.qpa.plugin: Could not find the Qt platform plugin "wayland" in ""
qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
also see [1] in the manual. Fix the package by using mkDerivation again.
[1]: https://nixos.org/manual/nixpkgs/unstable/#sec-language-qt
Fixes: fe1151218c ("chiaki: cleanup package")