Example on the main README doesn't work

[Nielius]

I'm new to Dhall and just found this repo, which looks like a great way to learn Dhall. Thanks!

It looks like the example from the quickstart doesn't work (anymore). The error I get:

dhall:
Error: Failed to resolve imports. Error list:


↳ ./toNetHack.dhall
  ↳ ./render/Config.dhall
    ↳ ./Prelude.dhall
      ↳ env:DHALL_PRELUDE

Error: Missing environment variable

↳ DHALL_PRELUDE


↳ ./toNetHack.dhall
  ↳ ./render/Config.dhall
    ↳ ./Prelude.dhall
      ↳ https://raw.githubusercontent.com/dhall-lang/dhall-lang/v8.0.0/Prelude/package.dhall sha256:0c04cbe34f1f2d408e8c8b8cb0aa3ff4d5656336910f7e86190a6d14326f966d
        ↳ https://raw.githubusercontent.com/dhall-lang/dhall-lang/v8.0.0/Prelude/Optional/package.dhall sha256:36a366af67a3c26cd5d196e095d3023f18953c5b5db3a03956fa554609e5442a
          ↳ https://raw.githubusercontent.com/dhall-lang/dhall-lang/v8.0.0/Prelude/Optional/all sha256:b9b015fe8be14da940901aa1510ee1d5e205df37ee651c32ac975a799782c410

Error: Unbound variable: Optional/fold

18│         Optional/fold

and then a whole lot of other unbound Optional/fold.

I updated the Prelude version in ./Prelude.dhall, but then I still got an error:

dhall text --file './example.dhall'
dhall:
↳ ./toNetHack.dhall
  ↳ ./render/Config.dhall
    ↳ ./render/Disclose.dhall

Error: Unbound variable: Optional/fold

10│         Optional/fold

/Users/niels.uitdebos/git/playground/dhall/dhall-nethack/render/Disclose.dhall:10:9

88│                                               ./Disclose.dhall

/Users/niels.uitdebos/git/playground/dhall/dhall-nethack/render/Config.dhall:88:47

but those were all the errors I got.

The file examples/small.dhall does seem to work, but it doesn't use toNetHack.

I'm on Mac and dhall version returns 1.34.0 (latest, it looks like).