Fix the shrinkJar task

build.gradle.kts

@@ -1,5 +1,6 @@
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 import com.modrinth.minotaur.request.VersionType
+import org.gradle.internal.jvm.Jvm
 buildscript {
     dependencies {
         classpath("com.guardsquare:proguard-gradle:7.1.0-beta2") {
@@ -40,13 +41,23 @@ subprojects {
             keep("class fr.username404.snowygui.fabric.** { * ; }")
             keep("class fr.username404.snowygui.forge.** { * ; }")
             keepclassmembers("class fr.username404.snowygui.** { public protected <methods>; }")
-            // TODO Fix kotlin
             keepattributes(); keepdirectories(); keeppackagenames(); keepparameternames()
             obfuscationdictionary("$dictionariesDir/dictionary.txt")
             classobfuscationdictionary("$dictionariesDir/classdictionary.txt")
             adaptclassstrings()
             "fr.username404.**".also { dontwarn(it); dontnote(it) }
-            dontwarn("java.**") // Needed for the current version of proguard
+
+            // The following lines are needed at least for the current version of proguard
+            dontwarn("java.**")
+            onlyIf {
+                JavaVersion.current().isJava8.also {
+                    if (it) {
+                        libraryjars("${Jvm.current().javaHome}/lib/rt.jar")
+                        libraryjars("${Jvm.current().javaHome}/lib/jce.jar")
+                    } else println("The shrinkJar task is disabled because Java 9 or higher does not work with our current proguard configuration.")
+                }
+            }
+
             // Note: dontpreverify() should NOT be used, it will cause errors at runtime
             useuniqueclassmembernames()
             optimizations("method/inlining/*, code/allocation/variable, class/merging/vertical, code/removal/advanced, code/simplification/branch, code/merging")
@@ -81,10 +92,12 @@ allprojects {
     }
     tasks {
         withType(ShadowJar::class) {
-            minimize {
-                exclude(project(":common"))
-            }
             relocate("kotlin", "${rootProject.group}.kotlin")
+            relocate("com.typesafe.config", "${rootProject.group}.typesafe.config")
+            relocate("io.github.config4k", "${rootProject.group}.config4k")
+            exclude("**/*.kotlin_metadata")
+            exclude("**/*.kotlin_builtins")
+            exclude("META-INF/maven/**/*")
             archiveClassifier.set("shadow")
         }
         withType(Jar::class) {