NixOS/nix — pull request #342 by VShell (2014-09-16 19:02:18+00:00)
Title: Install passthru set

This'll run `nix-env --set` instead of `nix-env --install` if `--set` is passed to nix-install-package. This can be used in, for example, an automatic update script that installs a new system derivation from a one-click-installer type file, allowing for flexible binary updates.