Issue description

The kernel module build seems not to be correctly sandboxed:

trace.txt

The use_blk_mq and mobile_lpm_policy modules that modinfo complains about are modules from my (building, but not nixos) local machine and not modules from the remote one, so there seems to be impureness happening when building modules. It’s reproduced with linuxPackages_latest and linuxPackages_hardened, both with sandbox = true and sandbox = relaxed. I’m not in a position to correctly test linuxPackages (I see no reason for it to be different though)

Steps to reproduce

Set boot.kernelPackages = pkgs.linuxPackages_latest in a nixops build, and try to build.

Technical details

• system: "x86_64-linux"
• host os: Linux 4.20.13-arch1-1-ARCH, Arch Linux, noversion
• multi-user?: yes
• sandbox: relaxed
• version: nix-env (Nix) 2.2.1
• channels(root): "nixpkgs-18.09.1834.9d608a6f592"
• channels(immae): ""
• nixpkgs: /nix/store/0ncif1fzmmcsx5f6h7c1ah9pzd8pgc10-nixexprs.tar.xz

(the nixpkgs version used to build the derivation was https://releases.nixos.org/nixos/19.03/nixos-19.03.172361.cf3e277dd0b/nixexprs.tar.xz )

cc @nh2