Build error in `src/GraphQL/Internal/Syntax/Parser.hs`: No instance for (ConvertText Text ByteString)

[sjakobi]

I'm seeing this build error with GHC 8.6.5:

src/GraphQL/Internal/Syntax/Parser.hs:167:8: error:
    • No instance for (ConvertText Text ByteString)
        arising from a use of ‘unescapeText’
    • In the expression: unescapeText parsed
      In a stmt of a 'do' block:
        case unescapeText parsed of
          Left err -> fail err
          Right escaped -> pure (AST.StringValue escaped)
      In the expression:
        do parsed <- char '"' *> jstring_
           case unescapeText parsed of
             Left err -> fail err
             Right escaped -> pure (AST.StringValue escaped)
    |
167 |   case unescapeText parsed of
    |        ^^^^^^^^^^^^^^^^^^^