Ensure nix-shell is usable and useful about rails-nix HOT 2 CLOSED

One issue I ran into when playing with nix-shell.

Ideally you can use bundlerEnv and bundix because it helps you install gems with native dependencies (postgres, nokogiri, etc). If you try to use bundle on its own, you need to know how to install these dependencies. So maybe it's worth exploring how to do the deps stuff using a custom command that would do bundle && bundix, then somehow reevaluate the shell so we get the correct environment.

If we decided it's too much work to support bundix, we need to set GEM_HOME and such, and figure out how to get the right native deps installed. That may not even do the trick given that some have specific build instructions in Nix for darwin.

from rails-nix.

A starter for this was done in fly-apps/nix-base#3. We can open more specific tickets for nodejs support.

from rails-nix.