ci: Update GitHub Actions and Scala version

.github/workflows/ci.yml

@@ -1,25 +1,24 @@
 name: test
 on:
   push:
-    branches:
-      - main
   pull_request:
 jobs:
   test:
     strategy:
       fail-fast: false
     runs-on: ubuntu-latest
+    env:
+      JVM_OPTS: "-Xms1024m -Xmx1024m -XX:ReservedCodeCacheSize=128m -XX:MaxPermSize=256m -Dfile.encoding=UTF-8"
     steps:
-    - uses: actions/checkout@v2
-    - uses: coursier/cache-action@v6
-    - uses: actions/setup-java@v2
+    - uses: actions/checkout@v7
+    - uses: actions/setup-java@v5
       with:
-        distribution: temurin
+        distribution: zulu
         java-version: 8
+        cache: sbt
+    - uses: sbt/setup-sbt@v1
     - name: Test
-      env:
-        JVM_OPTS: "-Xms1024m -Xmx1024m -XX:ReservedCodeCacheSize=128m -XX:MaxPermSize=256m"
       run: |
-        sbt "^test"
-        sbt "^publishLocal"
-        sbt "it:test"
+        sbt -v "^test"
+        sbt -v "^publishLocal"
+        sbt -v "it:test"

.java-version

@@ -0,0 +1 @@
+1.8

build.sbt

@@ -1,5 +1,6 @@
 import Dependencies._
 import RemoteDepHelper._
+import SbtSupport._
 
 def MyVersion: String = "0.9.20"
 
@@ -24,6 +25,19 @@ scmInfo in ThisBuild := Some(
     "scm:git:git@github.com:lightbend-labs/dbuild.git")
 )
 
+sbtLaunchJarLocation in ThisBuild := (baseDirectory in ThisBuild).value / "target" / "sbt" / "sbt-launch.jar"
+
+sbtLaunchJar in ThisBuild := {
+  val cp = (externalDependencyClasspath in (sbtLauncher, Compile)).value
+  val location = (sbtLaunchJarLocation in ThisBuild).value
+  cp.map(_.data).find(_.getName.startsWith("sbt-launch")) match {
+    case Some(x) =>
+      IO.copyFile(x, location)
+      Seq(location)
+    case None    => sys.error("failed to resolve sbt-launch")
+  }
+}
+
 def SubProj(name: String) = (
   Project(name, file(if (name=="root") "." else name))
   configs( IntegrationTest )
@@ -60,7 +74,7 @@ def skip212 = Seq(
 def selectScalaVersion =
   scalaVersion := {
     val sb = (sbtVersion in pluginCrossBuild).value
-    if (sb.startsWith("0.13")) "2.10.7" else "2.12.6"
+    if (sb.startsWith("0.13")) "2.10.7" else "2.12.21"
   }
 
 lazy val root = (
@@ -268,3 +282,13 @@ lazy val docs = (
     }).value
   )
 )
+
+lazy val sbtLauncher = (
+  SubProj("sbt-launcher")
+  settings(
+    autoScalaLibrary := false,
+    libraryDependencies += ("org.scala-sbt" % "sbt-launch" % "1.0.0").intransitive,
+    publish := (),
+    publishLocal := ()
+  )
+)

project/SbtSupport.scala

@@ -1,28 +1,12 @@
 import sbt._
 import Keys._
-import scala.concurrent.ExecutionContext.Implicits.global
 
 object SbtSupport {
   val sbtLaunchJarUrl = SettingKey[String]("sbt-launch-jar-url")
-  val sbtLaunchJarLocation = SettingKey[File]("sbt-launch-jar-location")  
-  val sbtLaunchJar = TaskKey[Seq[java.io.File]]("sbt-launch-jar", "Resolves SBT launch jar")
+  val sbtLaunchJarLocation = SettingKey[File]("sbt-launch-jar-location")
+  val sbtLaunchJar = TaskKey[Seq[java.io.File]]("sbt-launch-jar", "Resolves sbt launch jar")
 
-  def downloadFile(log: Logger, dbuildVersion:String, uri: String, file: File): Seq[File] = {
-    log.info("Downloading "+uri+" to "+ file.getAbsolutePath() +"...")
-    val ht = new com.typesafe.dbuild.http.HttpTransfer(dbuildVersion)
-    try {
-      ht.download(uri, file)
-    } finally {
-      ht.close()
-    }
-    Seq(file)
-  }
-
-  val buildSettings: Seq[Setting[_]] = Seq(
-    sbtLaunchJarUrl := "https://repo1.maven.org/maven2/org/scala-sbt/sbt-launch/1.0.0/sbt-launch.jar",
-    sbtLaunchJarLocation := baseDirectory.value / "target" / "sbt" / "sbt-launch.jar",
-    sbtLaunchJar := downloadFile(streams.value.log, version.value, sbtLaunchJarUrl.value, sbtLaunchJarLocation.value)
-  )
+  val buildSettings: Seq[Setting[_]] = Nil
   val settings: Seq[Setting[_]] = buildSettings ++ Seq(
     // The jar is added as a resource, so that the running dbuild can find it and use it to spawn new instances of sbt
     resourceGenerators in Compile += sbtLaunchJar.taskValue