Can't run qt applications after lastest upgrade

[pasqui23]

Issue description

After the lastest upgrade,any qt application I try to run fail at startup with the following error:

qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: minimal, offscreen, vnc, xcb, wayland-org.kde.kwin.qpa, minimal, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, xcb.

Steps to reproduce

1. Upgrade to the lastest version
2. Start any qt application via terminal

Technical details

• system: "x86_64-linux"
• host os: Linux 4.14.51, NixOS, 18.09pre143771.a8c71037e04 (Jellyfish)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.1pre6148_a4aac7f
• channels(root): "nixpkgs-18.09pre143771.a8c71037e04"
• channels(pasquale): "nixpkgs-19.03pre153158.7df10f388da"
• nixpkgs: /home/pasquale/.nix-defexpr/channels/nixpkgs

[pasqui23]

Resolved by bringing both the root and my personal channel to the same version