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.github/scripts/ci.sh

@@ -10,6 +10,8 @@ TEST_VERSION="0.1.0-test"
 echo "Running tests"
 sbt +test
 
+export COURSIER_INTERFACE_JAVA8_HOME="$(cs java-home --jvm 8)"
+
 IS_UNIX="false"
 case "$(uname -s)" in
   Linux*)     IS_UNIX="true";;

build.sbt

@@ -19,6 +19,8 @@ inThisBuild(List(
 
 lazy val finalPackageBin = taskKey[File]("")
 
+lazy val isJava9OrMore = sys.props.get("java.version").exists(!_.startsWith("1."))
+
 lazy val interface = project
   .enablePlugins(SbtProguard)
   .settings(
@@ -121,7 +123,6 @@ lazy val interface = project
         "-keep class coursierapi.** {\n  public protected *;\n}"
       )
 
-      val isJava9OrMore = sys.props.get("java.version").exists(!_.startsWith("1."))
       val maybeJava9Options =
         if (isJava9OrMore) {
           val javaHome = sys.props.getOrElse("java.home", ???)

project/Settings.scala

@@ -9,15 +9,29 @@ object Settings {
 
   def scala212 = "2.12.20"
 
+  private lazy val java8Home = Option(System.getenv("COURSIER_INTERFACE_JAVA8_HOME"))
+    .map(java.nio.file.Paths.get(_))
+    .getOrElse {
+      sys.error("COURSIER_INTERFACE_JAVA8_HOME not set")
+    }
+  private lazy val rtJar = {
+    val path = java8Home.resolve("jre/lib/rt.jar")
+    assert(java.nio.file.Files.exists(path))
+    path
+  }
   lazy val shared = Seq(
     scalaVersion := scala213,
     crossScalaVersions := Seq(scala213, scala212),
-    scalacOptions += "-target:jvm-1.8",
+    scalacOptions ++= Seq("--release", "8"),
     javacOptions ++= Seq(
-      "-source", "1.8",
-      "-target", "1.8"
+      "-source", "8",
+      "-target", "8",
+      "-bootclasspath", rtJar.toString
     ),
-    Compile / doc / javacOptions := Seq("-source", "1.8")
+    Compile / doc / javacOptions := Seq(
+      "-source", "8",
+      "-bootclasspath", rtJar.toString
+    )
   )
 
   private val filterOut = Set("0.0.1")