Deriving Show Compilation Error on Plutus Playground

Question

I seem to be getting a compilation error when I try to compile any of the example files on my local host configuration for the Plutus Playground. The error is pictured here: And basically it seems that no matter which example file I try and run I always end up getting a deriving show error. I am using an oracle VM and have installed the binaries for nix and have been running everything out of nix-shell.

Here is a better version of the error I've been receiving, this time on Week03's IsData.hs file, and I get the error at the 'Deriving Show' for MySillyRedeemer:

Then when I add the 'Show' to the Playground.Contract the error morphs into this:

So at this point I am really not sure what to do, all of these errors I encounter on my localhost server. I've reinstalled the plutus git and nix as well and I can't seem to figure out why I have these errors. And the errors do all seem to be 'not in scope' related so maybe its a a case of me not having certain files downloaded?

EDIT: Here is a copy of both the 'deriving show' error code:

error:
    Not in scope: type constructor or class ‘Show’
    Perhaps you want to add ‘Show’ to one of these import lists:
      ‘Prelude’ (/run/user/1000/web-ghc-work-f4d3c6b7d9d2297b/Main.hs:32:1-54)
      ‘Playground.Contract’ (/run/user/1000/web-ghc-work-f4d3c6b7d9d2297b/Main.hs:29:1-103)
   |
38 |     } deriving Show
   |                ^^^^

As well as one of the error code I get when I add 'Show' to the import list via Playground.Contract:

error:
    Not in scope: type constructor or class ‘Scripts.ScriptType’
    Module ‘Ledger.Typed.Scripts’ does not export ‘ScriptType’.
   |
59 | instance Scripts.ScriptType Vesting where
   |          ^^^^^^^^^^^^^^^^^^

Answer 1

I believe your issue is stemming from the fact that the plutus team is updating the plutus library relatively quickly, and since the code written in the plutus-pioneer-program is now a month or two old, it is outdated and will only compile on the older version of the plutus playground.

I suggest you keep using the publicly hosted playground and then eventually move over to cabal and the terminal.

Answer 2

You can run the Playground locally in Week 3 if you checkout the Plutus branch referenced in the Week03 cabal.project. See the tag option below.

source-repository-package
  type: git
  location: https://github.com/input-output-hk/plutus.git
  subdir:
    freer-extras
    playground-common
    plutus-core
    plutus-contract
    plutus-ledger
    plutus-ledger-api
    plutus-tx
    plutus-tx-plugin
    prettyprinter-configurable
    quickcheck-dynamic
  tag: 3aa86304e9bfc425667051a8a94db73fcdc38878

Answer 3

These are exactly the same errors that I get when I try to compile the Week 3 code with the latest Plutus master, so there is nothing wrong with your setup.

I was migrating the code to work with the master branch, but there have been a lot of Plutus changes since the Week 3 code was written which involved a lot of head scratching trying to figure out what was what.

As other posters have mentioned, checking out the correct commit should fix this for you.