···

       
1
       
1
       
 
       
if ! builtins ? nixVersion || builtins.compareVersions "1.8" builtins.nixVersion == 1 then

     

       
2
       
2
       
 
       


     

       
3
       
3
       
-
       
  abort "This version of Nixpkgs requires Nix >= 1.8, please upgrade!"

     

       
3
       
3
       
+
       
  abort "This version of Nixpkgs requires Nix >= 1.8, please upgrade! See https://nixos.org/wiki/How_to_update_when_nix_is_too_old_to_evaluate_nixpkgs"

     

       
4
       
4
       
 
       


     

       
5
       
5
       
 
       
else

     

       
6
       
6