not trying to be coy, but I don’t really understand it.
I had (and have) two .nixos-channels files; in ~ and in ~root (i.e./root). when it failed, they were different. when I made them identical (by softlinking, it worked.
the one in ~ is so I can git control the nixos setup. maybe it does something bad?
Never heard of .nixos-channels before. Is it analogue to nix-channel(1)? Is it documented somewhere? I cannot find any mention
of it in the NixOS manual.