qtwebkit marked as broken

[sjau]

Describe the bug
qtwebkit has been marked as broken for serveral weeks/months now.

To Reproduce
Steps to reproduce the behavior:

1. Try to build qtwebkit on nixos-unstable

error: Package ‘qtwebkit-5.212.0-alpha4’ in /nix/store/dkknbjkiilpxbqysnnf8pyvdrcjb7hhm-nixos-21.03pre255513.8ee7c2505f9/nixos/pkgs/development/libraries/qt-5/qtModule.nix:54 is marked as broken, refusing to evaluate.

a) To temporarily allow broken packages, you can use an environment variable
   for a single invocation of the nix tools.

     $ export NIXPKGS_ALLOW_BROKEN=1

b) For `nixos-rebuild` you can set
  { nixpkgs.config.allowBroken = true; }
in configuration.nix to override this.

c) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
  { allowBroken = true; }
to ~/.config/nixpkgs/config.nix.

(use '--show-trace' to show detailed location information)

Expected behavior
qtwebkit should build.

Notify maintainers
@abbradar
@periklis

Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

• system: "x86_64-linux"
• host os: Linux 5.4.62, NixOS, 20.09.git.61525137fd1 (Nightingale)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.3.7
• channels(hyper): "nixos-20.09pre242769.61525137fd1"
• channels(root): "nixos-21.03pre255513.8ee7c2505f9"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module: