with import <nixpkgs> {}; {
  env = stdenv.mkDerivation {
    name = "env";
    buildInputs = [
      elmPackages.elm
      cabal-install
      cabal2nix
      nodejs
      sqlite
      tmux
    ];
    shellHook = ''
      tmux kill-session -t sharedCost >/dev/null

      urxvt -e zsh -c "tmux new-session -s sharedCost" & sleep 0.5
      tmux send-keys -t sharedCost '"$EDITOR" README.md' 'C-m'

      tmux split-window -h -t sharedCost
      tmux send-keys -t sharedCost 'make install && make build && make watch' 'C-m'

      tmux select-pane -t sharedCost -L
      tmux resize-pane -t sharedCost -R 25

      firefox http://localhost:3000/

      sleep 0.5
      kill -9 $PPID
    '';
  };
}