# Nixpkgs that need --no-sandbox
**URL:** https://discourse.nixos.org/t/nixpkgs-that-need-no-sandbox/19173
**Category:** Development
**Created:** [May 16, 2022, 4:55am UTC](https://discourse.nixos.org/t/nixpkgs-that-need-no-sandbox/19173 "2022-05-16T04:55:50Z")
**Posts on this page:** 1
**Showing post:** 4
### Author:  [@NobbZ](https://discourse.nixos.org/u/NobbZ)
#### Post date: [May 16, 2022, 5:36am UTC](https://discourse.nixos.org/t/nixpkgs-that-need-no-sandbox/19173/4 "2022-05-16T05:36:49Z")
> [@wmarais](#):
>
> Hmm I think I found the attribute: [nix.conf](https://nixos.org/manual/nix/stable/command-ref/conf-file.html?highlight=sandbox#conf-sandbox)
Nope thats a configuration option.
Though I just checked the most recent release notes, the attribute I had in mind was not about the sandbox but impure derivations:
> [@Nix 2.8.0 released](https://discourse.nixos.org/t/nix-2-8-0-released/18714/1):
>
> New experimental feature: _impure derivations_ . These are derivations that can produce a different result every time they’re built. Here is an example:
>
> ```auto
> stdenv.mkDerivation {
> name = "impure";
> __impure = true; # marks this derivation as impure
> buildCommand = "date > $out";
> }
>
> ```
>
> Running `nix build` twice on this expression will build the derivation twice, producing two different content-addressed store paths. Like fixed-output derivations, impure derivations have access to the network. Only fixed-output derivations and impure derivations can depend on an impure derivation.
> [@Nix 2.8.0 released](https://discourse.nixos.org/t/nix-2-8-0-released/18714):
>
> Hi, I’m pleased to announce the availability of Nix 2.8.0. It will be available from [Download Nix / NixOS | Nix & NixOS](https://nixos.org/download.html). Here are the release notes: New experimental command: nix fmt, which applies a formatter defined by the formatter.\ flake output to the Nix expressions in a flake. Various Nix commands can now read expressions from standard input using --file -. New experimental builtin function builtins.fetchClosure that copies a closure from a binary cache at evaluation tim…
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