nix-instantiate: pass pos in the `--eval --json` code path
nix-instantiate: pass pos in the `--eval --json` code path

rycee/nix,NixOS/nix,rycee/nix,rycee/nix,rycee/nix,NixOS/nix,NixOS/nix,NixOS/nix,NixOS/nix,rycee/nix