IDK that this is related to #188 or not! BTW, I'm using Nix 2.3.3 and `snack build` inside nix-shell exits with the following error: ```bash error: cannot coerce a set to a string, at /nix/store/43mrc82ajh3nxdjb7k9z6vslpjb2fjdx-source/lib/strings.nix:369:26 ```