An empty nix channel in channel-list

At some point, I borked my nix channels. When I run nix-channel --list I get two entries:

" "
nixos https://nixos.org/channels/nixos-unstable

I can’t remove the blank entry with nix-channel --remove " ". I get:

warning: selector ' ' matched no installed derivations

I can no longer run nixos-rebuild without explicitly specifying a NIX_PATH. I’m guessing that this erroneous channel is the reason why.

Does anyone know how I can clean this up?

Okay, so it turned out I just needed to edit ~/.nix-channel to remove the bad line.