[neo@nixos:~]$ nix-channel --update

downloading Nix expressions from ‘https://d3g5gsiof5omrk.cloudfront.net/nixpkgs/nixpkgs-17.09pre112229.e619ace733/nixexprs.tar.xz’...

downloading ‘https://d3g5gsiof5omrk.cloudfront.net/nixpkgs/nixpkgs-17.09pre112229.e619ace733/nixexprs.tar.xz’... [4271/8878 KiB, 4268.8 KiB/s]

downloading Nix expressions from ‘https://nixos.org/channels/nixpkgs/nixexprs.tar.bz2’...

downloading ‘https://nixos.org/channels/nixpkgs/nixexprs.tar.bz2’... [0/0 KiB, 0.0 KiB/s]

error: unable to download ‘https://nixos.org/channels/nixpkgs/nixexprs.tar.bz2’: HTTP response code said error (22)

cannot fetch ‘https://nixos.org/channels/nixpkgs/nixexprs.tar.bz2’