I  ~  sudo nixos-rebuild switch --keep-going                                                     41s  Fri 23 Mar 2018 09:19:00 PM MST
these paths will be fetched (0.00 MiB download, 0.01 MiB unpacked):
  /nix/store/dg6pq2zwgnahb95a9zifkf0alk28qkmh-nixos-rebuild
fetching path ‘/nix/store/dg6pq2zwgnahb95a9zifkf0alk28qkmh-nixos-rebuild’...

*** Downloading ‘https://cache.nixos.org/nar/03ha9wb93hni4h61r82ad7zkkhhan9l1rysx3v4hzrrv63c6p8kd.nar.xz’ (signed by ‘cache.nixos.org-1’) to ‘/nix/store/dg6pq2zwgnahb95a9zifkf0alk28qkmh-nixos-rebuild’...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  3876  100  3876    0     0  10308      0 --:--:-- --:--:-- --:--:-- 10308

building Nix...
/nix/store/dg6pq2zwgnahb95a9zifkf0alk28qkmh-nixos-rebuild/bin/nixos-rebuild: line 317: /tmp/nixos-rebuild.KTVVIO/nix/bin/nix-instantiate: cannot execute binary file: Exec format error
building the system configuration...
/nix/store/dg6pq2zwgnahb95a9zifkf0alk28qkmh-nixos-rebuild/bin/nixos-rebuild: line 142: /tmp/nixos-rebuild.KTVVIO/nix/bin/nix-build: cannot execute binary file: Exec format error