pypy3.withPackages works differently?

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1

I was trying to add a shell.nix to this small personal project, and I got this working:

with (import <nixpkgs> {});

mkShell {
  buildInputs = [

    (python312.withPackages (python-pkgs: [
      python-pkgs.sympy
      python-pkgs.colorama
      (python-pkgs.buildPythonPackage rec {
        pname = "kociemba";
        version = "1.2.1";

        src = python-pkgs.fetchPypi {
          inherit pname version;
          hash = "sha256-t3Q117DpPpx5Y+SH6Mw4IFQL0cm7n+VmWZnTqN6snuY=";
        };

        pyproject = true;
        dependencies = [
          python-pkgs.cffi
        ];
        build-system = [
          python-pkgs.cffi
          python-pkgs.future
          python-pkgs.pytest-runner
          python-pkgs.setuptools
        ];

      })

    ]))
  ];
}

However, when I go in and replace “python312” with “pypy310”, then pypy3 is unable to see or import the python packages like sympy or kociemba — despite the fact that compilation seemed to succeed!

Is due to this a mistake in my derivation, or a bug in the upstream pypy310 package?