如何使用 nix-shell 从 PyPi 安装 playwright？

如何解决如何使用 nix-shell 从 PyPi 安装 playwright？

我正在尝试创建一个安装 nix-shell 和 python 的 playwright。我的代码确实安装了 python，但我无法正确安装 playwright。

with (import <nixpkgs> {});

let
  playwright = pkgs.python38Packages.buildPythonPackage rec {
    pname = "playwright";
    version = "1.12.1";

    src = pkgs.python38Packages.fetchPypi {
      inherit pname version;
    };

    propagatedBuildInputs = with pkgs.python38Packages; [];

    doCheck = false;
  };

  customPython = pkgs.python38.buildEnv.override {
    extraLibs = [ playwright ];
  };
in

pkgs.mkShell {
  buildInputs = [ customPython ];
}

这给了我以下错误：

while evaluating the attribute 'outPath' at /nix/store/gjqpc2i5nbi1yrzm0caaryvs8y1nhc8h-nixpkgs-21.11pre292293.84aa23742f6/nixpkgs/lib/customisation.nix:164:7:
while evaluating the attribute 'src' of the derivation 'python3.8-playwright-1.12.1' at /nix/store/gjqpc2i5nbi1yrzm0caaryvs8y1nhc8h-nixpkgs-21.11pre292293.84aa23742f6/nixpkgs/pkgs/stdenv/generic/make-derivation.nix:201:11:
hash '' has wrong length for hash type 'sha256'

如何修复它的哈希值？