Stack user guide is incompatible with the current stack-to-nix

[qrilka]

In https://github.com/input-output-hk/haskell.nix/blob/master/docs/user-guide-stack.md I see stack-to-nix invoked as

stack-to-nix -o nix stack.yaml > nix/.stack-pkgs.nix

But the version in the current master shows the following help:

stack-to-nix - a stack to nix converter

Usage: stack-to-nix (-o|--output DIR) [--stack-yaml FILE] [--cache FILE]
  Generate a Nix expression for a Haskell package using Stack

Available options:
  -o,--output DIR          Generate output in DIR
  --stack-yaml FILE        Override project stack.yaml (default: "stack.yaml")
  --cache FILE             Dependency cache
                           file (default: ".stack-to-nix.cache")
  -h,--help                Show this help text

and also it doesn't appear to produce anything to stdout.
Is it some older version maybe?

[rvl]

Thanks for reporting @qrilka. We hadn't yet updated it because the docs PR and nix-tools PR were open at the same time.