[flakes] NIX_PATH impurity

[roberth]

Running

$ NIX_PATH= nixops deploy -d nixops-example-dummy --build-only

I get error: file 'nixpkgs/nixos/modules/virtualisation/ec2-amis.nix' was not found in the Nix search path (add it using $NIX_PATH or -I), even without actually using nixops-aws; module system import resolution must be able to get all imports.

This is an impurity, which is a bug since flakes. It should be taken from network.nixpkgs instead.

[Uthar]

I had this problem too, fixed it like this:

1. Uthar/nixops@eff4449
2. Uthar@c149649

Uthar@c149649#diff-41b598abd0ad034083691ba71cbf1a0280064be95e76e0a43b0d9df7664cdfff
is still hardcoded against <nixpkgs> though, but in my case it was fine