NixOS/nixpkgs — pull request #3880 by copumpkin (2014-08-30 21:28:39+00:00)
Title: Add xar

http://en.wikipedia.org/wiki/Xar_(archiver)

The smlnj package currently implicitly depends on xar being present (https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/compilers/smlnj/bootstrap.nix#L16). I'll submit another PR to fix that shortly.