I am new to haskell and I am trying to run a few expressions from the English Auction Contract in the repl.

So if I want to run ValidatorHash "f" from the second last line of the Contract in week01, how do I do it in the repl here [nix-shell:~/plutus-pioneer-program/code/week01]$ cabal repl?

What I tried

> import Ledger.ValidatorHash
> Ledger.ValidatorHash "f"
error: Couldn't match expected type ‘PlutusTx.Builtins.Internal.BuiltinByteString’
                  with actual type ‘[Char]’

then

> import PlutusTx.Builtins.Internal
> Ledger.ValidatorHash (BuiltinByteString "f")
error: Couldn't match expected type ‘bytestring-0.10.12.0:Data.ByteString.Internal.ByteString’
                  with actual type ‘[Char]’

then

> import Data.ByString as BS
error: Could not find module ‘Data.ByString’
    Perhaps you meant
      Data.ByteString (needs flag -package-key bytestring-0.10.12.0)
      Data.String (from base-4.14.1.0)

So do I really need to close this repl and figure out the way to open the repl with the flag? Or is there something very obvious that I am missing?