Failing to resolve www.python.org?

[Supergamer1337]

I'm trying to install python 3.7 by using the following

environment.systemPackages = [
	nixpkgs-python.packages.x86_64-linux."3.6"
];

But I get the following error when I do

error: builder for '/nix/store/087dc65vagvbvn2il54pm881119l1p0q-Python-3.6.15.tar.xz.drv' failed with exit code 1;
       last 10 log lines:
       >   % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
       >                                  Dload  Upload   Total   Spent    Left  Speed
       >   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
       > Warning: Problem : timeout. Will retry in 1 seconds. 3 retries left.
       >   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
       > Warning: Problem : timeout. Will retry in 2 seconds. 2 retries left.
       >   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
       > Warning: Problem : timeout. Will retry in 4 seconds. 1 retries left.
       >   0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
       > error: cannot download Python-3.6.15.tar.xz from any mirror
       For full logs, run 'nix log /nix/store/087dc65vagvbvn2il54pm881119l1p0q-Python-3.6.15.tar.xz.drv'.

Using flakes on nixos. Any ideas?

[domenkozar]

Can you prove a full flake?

[pinarruiz]

Same here:

trying https://www.python.org/ftp/python/3.13.4/Python-3.13.4.tar.xz
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
^M  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
Warning: Problem : timeout. Will retry in 1 second. 3 retries left.
^M  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
Warning: Problem : timeout. Will retry in 2 seconds. 2 retries left.
^M  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
Warning: Problem : timeout. Will retry in 4 seconds. 1 retry left.
^M  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0curl: (6) Could not resolve host: www.python.org
error checking the existence of https://tarballs.nixos.org//:
curl: (6) Could not resolve host: tarballs.nixos.org
error: cannot download Python-3.13.4.tar.xz from any mirror

{
inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.05";

    nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";

    systems.url = "github:nix-systems/default";

    flake-parts.url = "github:hercules-ci/flake-parts";

    flake-compat.url = "github:edolstra/flake-compat";

    home-manager = {
      url = "github:nix-community/home-manager/release-25.05";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    agenix = {
      url = "github:ryantm/agenix/0.15.0";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        darwin.follows = "";
        home-manager.follows = "home-manager";
      };
    };

    stylix = {
      url = "github:nix-community/stylix/release-25.05";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        home-manager.follows = "home-manager";
        systems.follows = "systems";
        flake-parts.follows = "flake-parts";
        flake-compat.follows = "flake-compat";
      };
    };

    flake-utils = {
      url = "github:numtide/flake-utils";
      inputs.systems.follows = "systems";
    };

    android-nixpkgs = {
      url = "github:tadfisher/android-nixpkgs/stable";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-utils.follows = "flake-utils";
        devshell.follows = "";
      };
    };

    glaumar = {
      url = "github:glaumar/nur";
      inputs = { nixpkgs.follows = "nixpkgs"; };
    };

    nixvim-standalone = {
      url = "path:./common/nvim";
      inputs = {
        nixpkgs.follows = "nixpkgs-unstable";
        flake-utils.follows = "flake-utils";
        flake-parts.follows = "flake-parts";
        systems.follows = "systems";
      };
    };

    nixpkgs-python = {
      url = "github:cachix/nixpkgs-python";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-compat.follows = "flake-compat";
      };
    };
  };

...
python313 = inputs.nixpkgs-python.packages."${system}"."3.13.4";
...

}

I am using it as an overlay.

Edit: add some more context.

[pinarruiz]

It seems to be a sandboxing issue, as doing:

--option sandbox false

makes it succeed.

From a quick look it seems the issue is the fetchurl inside of the mkPython function, but i have not taken a proper look.

Edit: add more information

[pinarruiz]

Related to #12 ?