gistfile1.txt

[root@nixos:~]$ nix-shell -p nix-info --run "nix-info -m"
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignoring
error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I), at (string):1:13

[root@nixos:~]$ ls /nix/var/nix/profiles/per-user/root/channels/
manifest.nix

[root@nixos:~]$ nix-channel --list
nixos https://nixos.org/channels/nixos-unstable-small

[root@nixos:~]$ nix-shell -I nixpkgs=/root/nixpkgs/ -p nix-info --run "nix-info -m"
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignoring
error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I), at (string):1:9
 - system: `0`
 - host os: `Linux 4.14.87, NixOS, 19.03.git.ed46fe4 (Koi)`
 - multi-user?: `no`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.1.3`
 - channels(root): `""`
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/nixos' does not exist, ignoring
error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I), at (string):1:1
 - nixpkgs: `0`