Describe the bug

e.g.

error: Trying to register a realisation of 'sha256:f688836440b883b488ddface781bb6c70d424dc299c6b1fca7fa3db430edb084!out', but we already have another one locally.
       Local:  /nix/store/z951kjzqb5qg49vix966r7dg7ccy34zk-perl5.34.0-libnet-3.12
       Remote: /nix/store/fcfx1jfrxzfpszk4r0nj456nck0911px-perl5.34.0-libnet-3.12

This issue has a low priority, but it is annoying nonetheless.

Steps To Reproduce

Steps to reproduce the behavior:
build the above mentioned package (I'm not really sure which dependency graph part introduces it) on multiple different machines. maybe even rechecking on the same machine suffices.

Expected behavior

The package should be reproducible. It does not seem to contain binary artifacts, so that should be relatively easy, I suppose...

Additional context

  libnet = buildPerlPackage {
    pname = "libnet";
    version = "3.12";
    src = fetchurl {
      url = "mirror://cpan/authors/id/S/SH/SHAY/libnet-3.12.tar.gz";
      sha256 = "1px35q9qchzd7rxqldj87vbrall8v31blidhmh0d25d5hyq9lw25";
    };
    meta = {
      description = "Collection of network protocol modules";
      license = with lib.licenses; [ artistic1 gpl1Plus ];
    };
  };

Notify maintainers

Metadata

[user@system:~]$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 5.10.68, NixOS, 21.11 (Porcupine)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.5pre20211007_844dd90`
 - nixpkgs: `/etc/nix-flake-channels/nixpkgs`

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module: