fetching path `/nix/store/fw4bgblnpvzq914cgall3k3553p6wmgi-libarchive-3.1.2'...

*** Downloading ‘http://cache.nixos.org/nar/180p213q50x3blmyy7yq3zzjhn07ibclpk09rqqphlglf8ncjllb.nar.xz’ to ‘/nix/store/fw4bgblnpvzq914cgall3k3553p6wmgi-libarchive-3.1.2’...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   797  100   797    0     0    716      0  0:00:01  0:00:01 --:--:--   718
/nix/store/y2lsw31p99nyxqzs2cb6hb97x7dp2pnq-xz-5.0.5/bin/xz: (stdin): File format not recognized
error: unexpected end-of-file
download of `http://cache.nixos.org/nar/180p213q50x3blmyy7yq3zzjhn07ibclpk09rqqphlglf8ncjllb.nar.xz' failed: No such file or directory
could not download ‘/nix/store/fw4bgblnpvzq914cgall3k3553p6wmgi-libarchive-3.1.2’ from any binary cache
fetching path `/nix/store/fw4bgblnpvzq914cgall3k3553p6wmgi-libarchive-3.1.2' failed with exit code 1
error: some substitutes for the outputs of derivation `/nix/store/2dh2zscaiawsifnd2xdxa5j9c488pnfq-cmake-2.8.12.2.drv' failed (usually happens due to networking issues); try `--fallback' to build derivation from source