attribute sha256 missing

[turboMaCk]

Thanks for implementing and publishing the library.

I've run into an issue when trying to use it with dart-sass-emebedded project.

       at /nix/store/rqwcgd6ia6n5ws2axl4ib4w14z4z6dyv-source/build.nix:41:36:

           40|           ];
           41|           nixStorePath = fetchzip {
             |                                    ^
           42|             inherit (package) sha256;

I'm using:

• nix (Nix) 2.13.2
• flake-utils 5aed5285a952e0b949eb3ba02c12fa4fcfef535f
• nix-dart 6f686dd

[farcaller]

That might happen if your dependency isn't a pub.dev public dependency, but points at a path or a git repo.