How to package Scala 3 application using the "scopt" library with "Proguard"? - scala

Question

The moment I add a dependency on the scopt library to my Scala 3 application, I am no longer able to successfully package it using Proguard. Upon attempting to run an executable jar, I am only seeing the following error message:
Exception in thread "main" java.lang.VerifyError: Bad invokespecial instruction: interface method reference is in an indirect superinterface.
Exception Details:
Location:
scala/collection/SeqFactory$Delegate.tabulate(ILscala/Function1;)Ljava/lang/Object; #9: invokespecial
Reason:
Error exists in the bytecode
Bytecode:
0000000: 2a1b 2c4e 3d59 4c1c 2db7 000a b0
at scopt.OptionDef.<init>(OptionDef.scala:52)
at scopt.OptionDef.<init>(OptionDef.scala:63)
at HelloWorld$.<clinit>(HelloWorld.scala:1082)
at HelloWorld.main(HelloWorld.scala)
Here is the minimal example to reproduce the issue:
$ cat build.sbt
lazy val root = (project in file(".")).
settings(
name := "helloworld",
scalaVersion := "3.1.1"
)
libraryDependencies ++= Seq(
"com.github.scopt" %% "scopt" % "4.0.1"
)
enablePlugins(SbtProguard)
Proguard / proguardFilteredInputs ++= ProguardOptions.noFilter((Compile / packageBin).value)
Proguard / proguardInputs := (Compile / dependencyClasspath).value.files
Proguard / proguardOptions += ProguardOptions.keepMain("HelloWorld")
Proguard / proguardOptions += ProguardConf.helloWorld
Proguard / proguardVersion := "7.2.0"
$ cat project/ProguardConf.scala
object ProguardConf {
val helloWorld =
"""
-dontnote
-dontobfuscate
-dontwarn java.lang.invoke.MethodHandle
-dontwarn scala.AnyKind
-libraryjars <java.home>/jmods
"""
}
$ cat project/build.properties
sbt.version=1.6.2
$ cat project/plugins.sbt
addSbtPlugin("com.github.sbt" % "sbt-proguard" % "0.5.0")
$ cat src/main/scala/HelloWorld.scala
import scopt.OParser
case class Config(name: String)
object HelloWorld {
private val parser = OParser.sequence(
OParser.builder[Config]
.opt[String]("name")
.action((value: String, option: Config) => option.copy(name = value)))
def main(args: Array[String]) = {
OParser.parse(parser, args, Config("World")) match {
case Some(config) => {
println(s"Hello ${config.name}")
}
case None =>
}
}
}
I am packaging and running it like this:
$ sbt
sbt:helloworld> proguard:proguard
Ctrl-D
$ java -jar target/scala-3.1.1/proguard/helloworld_3-0.1.0-SNAPSHOT.jar
Any clues what might I have been missing? Many thanks!