create-elm-app + elm 0.19 on NixOS

install.sh

# These instructions assume you are on https://nixos.org/channels/nixos-18.09
# You will need $HOME/bin in your $PATH to use create-elm-app

# Create a empty nix profile
nix-env -S /nix/var/nix/profiles/per-user/$USER/elm19-app

# Install elm 0.19
nix-env -iA nixos.elmPackages

# Keep global node packages in $HOME, will result in bin, lib and node_packages dirs
npm set prefix $HOME

# Update npm, install create-elm-app
npm i npm@latest -g
npm i create-elm-app -g

# Replace the wrappers with symlinks to system elm
cd ~/lib/node_modules/create-elm-app/node_modules/elm/bin
rm -f elm
ln -s (which elm) .