possible bug in documentation with `@derives[Parser, Help]`

[kuba86]

Looking at the documentation https://alexarchambault.github.io/case-app/define/ there is a suggestion "When defining a case class for options, it is recommended to derive case-app type classes for it in its companion object, like"

case class Options(
  foo: Int
)

// Scala 2
object Options {
  implicit lazy val parser: Parser[Options] = Parser.derive
  implicit lazy val help: Help[Options] = Help.derive
}

// Scala 3
@derives[Parser, Help]
object Options

When running the following example:

//> using scala "3"
//> using dependency "com.github.alexarchambault::case-app:2.1.0"

import caseapp.*

case class Options(
  foo: Int
)

@derives[Parser, Help]
object Options

object MyApp extends CaseApp[Options] {
  def run(options: Options, remaining: RemainingArgs): Unit = {
    println(options)
  }
}

there will be a compilation error:

scala-cli run . -- run --foo=7
Compiling project (Scala 3.8.1, JVM (21))
[error] ./caseapp.scala:10:2
[error] Not found: type derives
[error] @derives[Parser, Help]
[error]  ^^^^^^^
Error compiling project (Scala 3.8.1, JVM (21))
Compilation failed

by removing

@derives[Parser, Help]
object Options

the code compiles correctly.

What would be a proper way to use @derives in CaseApp with Scala 3 to meet the goal for "we highly recommend deriving them there, in order to make incremental compilation faster when the file defining the options isn't modified."