nix shell shebang support doesn't work

[cdmistman]

Describe the bug

using nix shell in shebang position as documented doesn't actually work!

Steps To Reproduce

1. Create a file foo.sh with the following content:

#!/usr/bin/env nix
#! nix shell nixpkgs#bash nixpkgs#hello nixpkgs#cowsay --command bash

hello | cowsay

2. chmod +x foo.sh
3. ./foo.sh
4. Error:

error: './foo.sh' is not a recognised command
Try 'nix --help' for more information.

Expected behavior

Running foo.sh should result in the same output as nix shell nixpkgs#{bash,hello,cowsay} -c bash -c 'hello | cowsay'

nix-env --version output nix-env (Nix) 2.18.1

Priorities

Add :+1: to issues you find important.

[alois31]

nix-env --version output nix-env (Nix) 2.18.1

This feature was only introduced in 2.19.

[tomberek]

Prior to 2.19 only the previous nix-shell shebang worked. Closing as answered.