Sbt task for picocli graalvm reflection generation?

Question

In picocli they give examples on how to generate GraalVM reflection configurations during the build for Maven and Gradle.

Gradle example

configurations {
    generateConfig
}
dependencies {
    compile 'info.picocli:picocli:3.9.3'
    generateConfig 'info.picocli:picocli-codegen:3.9.3'
}

task

task(generateGraalReflectionConfig, dependsOn: 'classes', type: JavaExec) {
    main = 'picocli.codegen.aot.graalvm.ReflectionConfigGenerator'
    classpath = configurations.generateConfig + sourceSets.main.runtimeClasspath
    def outputFile = new File(project.buildDir, 'cli-reflect.json')
    args = ["--output=$outputFile", 'com.your.package.YourCommand1', 'com.your.package.YourCommand2']
}
assemble.dependsOn generateGraalReflectionConfig

How could I write something equivalent for sbt ?

This is what I got so far but I don't know if I'm going in the right direction.

import Dependencies._

ThisBuild / scalaVersion := "2.12.8"
ThisBuild / version := "0.1.0-SNAPSHOT"
ThisBuild / organization := "com.example"
ThisBuild / organizationName := "example"

lazy val root = (project in file("."))
  .settings(
    name := "poc-cli",
    libraryDependencies += scalaTest % Test,
    libraryDependencies += "info.picocli" % "picocli" % "3.9.3",
    libraryDependencies += "info.picocli" % "picocli-codegen" % "3.9.3",
  )

lazy val graalConfig = inputKey[Unit]("gen-graal-config") 

graalConfig:= {
    val conf = (runMain in Compile).fullInput(" picocli.codegen.aot.graalvm.ReflectionConfigGenerator --output=cli-reflect.json example.Hello").evaluated
}

enablePlugins(GraalVMNativeImagePlugin)

Edit

in my initial question, I had the code below, with my current code the problem is solved

lazy val graalConfig = taskKey[Unit]("graal-config") := {
    Process("java" :: "-jar" :: "picocli.codegen.aot.graalvm.ReflectionConfigGenerator" :: "--output" :: "cli-reflect.json" :: "???" :: Nil,
        baseDirectory.value / "lib").!
}

Answer 1

The solution was

import Dependencies._


ThisBuild / scalaVersion := "2.12.8"
ThisBuild / version := "0.1.0-SNAPSHOT"
ThisBuild / organization := "com.example"
ThisBuild / organizationName := "example"

lazy val root = (project in file("."))
  .settings(
    name := "poc-cli",
    libraryDependencies += scalaTest % Test,
    libraryDependencies += "info.picocli" % "picocli" % "3.9.3",
    libraryDependencies += "info.picocli" % "picocli-codegen" % "3.9.3",
  )

lazy val graalConfig = inputKey[Unit]("gen-graal-config")

graalVMNativeImageOptions += "-H:ReflectionConfigurationFiles=../cli-reflect.json"

graalConfig:= {
    (runMain in Compile).fullInput(" picocli.codegen.aot.graalvm.ReflectionConfigGenerator -o=target/cli-reflect.json example.Hello").evaluated
}

enablePlugins(GraalVMNativeImagePlugin)

then I can run:

$ sbt graalConfig
$ sbt graalvm-native-image:packageBin