This fixes extra arguments. Before, you'd see this if you tried to use any arguments with nix-shell or nix develop:
$ nix develop --command whatever
error: unexpected argument '--command' found
note: to pass '--command' as a value, use '-- --command'
Usage: nix-your-shell <SHELL> nix <ARGS>
For more information, try '--help'.
This fixes extra arguments. Before, you'd see this if you tried to use any arguments with
nix-shell
ornix develop
: