Installer should tell if xz is missing

[domenkozar]

# bash <(curl -L https://nixos.org/nix/install)
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  2399  100  2399    0     0   3850      0 --:--:-- --:--:-- --:--:--  3856
downloading Nix 2.3.4 binary tarball for x86_64-linux from ‘https://nixos.org/releases/nix/nix-2.3.4/nix-2.3.4-x86_64-linux.tar.xz' to ‘/tmp/nix-binary-tarball-unpack.7rCTvikCiv’...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    86  100    86    0     0    156      0 --:--:-- --:--:-- --:--:--   156
100 16.4M  100 16.4M    0     0  3203k      0  0:00:05  0:00:05 --:--:-- 3905k
tar (child): xz: Cannot exec: No such file or directory
tar (child): Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error is not recoverable: exiting now
/dev/fd/63: failed to unpack ’https://nixos.org/releases/nix/nix-2.3.4/nix-2.3.4-x86_64-linux.tar.xz'

[matthewbauer]

I thought this was fixed by #3431

[domenkozar]

Ah, in that case it needs to be deployed.