Build sbt/sbt using sbt 2

.github/workflows/client-test.yml

@@ -54,11 +54,11 @@ jobs:
         # test building sbtn on Linux (sbtw native-image dropped: scopt lazy vals break under Graal)
         sbt "-Dsbt.io.virtual=false" nativeImage
         # smoke test native Image
-        ./client/target/bin/sbtn --sbt-script=$(pwd)/sbt about
-        ./client/target/bin/sbtn --sbt-script=$(pwd)/sbt shutdown
+        ./target/out/jvm/u/sbt-client/bin/sbtn --sbt-script=$(pwd)/sbt about
+        ./target/out/jvm/u/sbt-client/bin/sbtn --sbt-script=$(pwd)/sbt shutdown
         # test launcher script
         echo build using JDK 17 test using JDK 17 and JDK 25
-        sbt -Dsbt.build.version=$TEST_SBT_VER launcherPackage/Rpm/packageBin launcherPackage/Debian/packageBin
+        sbt --server -Dsbt.build.version=$TEST_SBT_VER launcherPackage/Rpm/packageBin launcherPackage/Debian/packageBin
         sbt -Dsbt.build.version=$TEST_SBT_VER launcherPackageIntegrationTest/test
         cd launcher-package/citest && ./test.sh
         JAVA_HOME="$JAVA_HOME_25_X64"
@@ -91,8 +91,8 @@ jobs:
       shell: bash
       run: |
         # smoke test native Image (sbtn)
-        ./client/target/bin/sbtn --sbt-script=$(pwd)/launcher-package/src/universal/bin/sbt.bat about
-        ./client/target/bin/sbtn --sbt-script=$(pwd)/launcher-package/src/universal/bin/sbt.bat shutdown
+        ./target/out/jvm/u/sbt-client/bin/sbtn --sbt-script=$(pwd)/launcher-package/src/universal/bin/sbt.bat about
+        ./target/out/jvm/u/sbt-client/bin/sbtn --sbt-script=$(pwd)/launcher-package/src/universal/bin/sbt.bat shutdown
         # test launcher script
         echo build using JDK 17 test using JDK 17 and JDK 25
         launcher-package/bin/coursier.bat resolve

.scalafmt.conf

@@ -29,11 +29,11 @@ rewrite.scala3.newSyntax.control = false
 
 fileOverride {
   "glob:**/project/**" {
-    runner.dialect = scala212source3
+    runner.dialect = scala3
     runner.dialectOverride.allowAsForImportRename = false
   }
   "glob:**/*.sbt" {
-    runner.dialect = scala212source3
+    runner.dialect = scala3
     runner.dialectOverride.allowAsForImportRename = false
   }
 }

build.sbt

@@ -91,7 +91,7 @@ def commonSettings: Seq[Setting[?]] = Def.settings(
       import scala.sys.process.*
       val devnull = ProcessLogger(_ => ())
       val tagOrSha =
-        ("git describe --exact-match" #|| "git rev-parse HEAD").lineStream(devnull).head
+        ("git describe --exact-match" #|| "git rev-parse HEAD").lazyLines(devnull).head
       Seq(
         "-source-links:github://sbt/sbt",
         "-revision",
@@ -214,7 +214,7 @@ lazy val sbtRoot: Project = (project in file("."))
           }
       }
       val base = baseDirectory.value.toPath
-      val exec = (sbtClientProj / nativeImage).value.toPath
+      val exec = fileConverter.value.toPath((sbtClientProj / nativeImage).value)
       streams.value.log.info(s"installing thin client ${base.relativize(exec)} to ${target}")
       Files.copy(exec, target, java.nio.file.StandardCopyOption.REPLACE_EXISTING)
     }
@@ -447,6 +447,7 @@ lazy val workerProj = (project in file("worker"))
   .dependsOn(exampleWorkProj % Test)
   .settings(
     name := "worker",
+    Test / classLoaderLayeringStrategy := ClassLoaderLayeringStrategy.Raw,
     testedBaseSettings,
     Compile / doc / javacOptions := Nil,
     crossPaths := false,
@@ -693,6 +694,7 @@ lazy val buildFileProj = (project in file("buildfile"))
     mainSettingsProj,
   )
   .settings(
+    exportJars := false,
     testedBaseSettings,
     name := "build file",
     libraryDependencies ++= Seq(scalaCompiler),
@@ -843,7 +845,11 @@ lazy val serverTestProj = (project in file("server-test"))
     Test / run / fork := true,
     Test / sourceGenerators += Def.task {
       val rawClasspath =
-        (Compile / fullClasspathAsJars).value.map(_.data).mkString(java.io.File.pathSeparator)
+        (Compile / fullClasspathAsJars).value
+          .map(_.data)
+          .map(fileConverter.value.toPath)
+          .map(_.toFile.getAbsolutePath)
+          .mkString(java.io.File.pathSeparator)
       val cp =
         if (scala.util.Properties.isWin) rawClasspath.replace("\\", "\\\\")
         else rawClasspath
@@ -861,7 +867,7 @@ lazy val serverTestProj = (project in file("server-test"))
       val file =
         (Test / target).value / "generated" / "src" / "test" / "scala" / "testpkg" / "TestProperties.scala"
       IO.write(file, content)
-      file :: Nil
+      Seq(file)
     },
   )
 
@@ -897,7 +903,7 @@ lazy val sbtClientProj = (project in file("client"))
       if (!Files.exists(outputDir)) {
         Files.createDirectories(outputDir)
       }
-      outputDir.resolve("sbtn").toFile
+      fileConverter.value.toVirtualFile(outputDir.resolve("sbtn"))
     },
     nativeImageCommand := {
       val orig = nativeImageCommand.value
@@ -1003,6 +1009,7 @@ lazy val sbtIgnoredProblems = {
 def scriptedTask(launch: Boolean): Def.Initialize[InputTask[Unit]] = Def.inputTask {
   val _ = publishLocalBinAll.value
   val launchJar = s"-Dsbt.launch.jar=${(bundledLauncherProj / Compile / packageBin).value}"
+  val converter = fileConverter.value
   Scripted.doScripted(
     (scriptedSbtProj / scalaInstance).value,
     scriptedSource.value,
@@ -1014,10 +1021,12 @@ def scriptedTask(launch: Boolean): Def.Initialize[InputTask[Unit]] = Def.inputTa
     version.value,
     (scriptedSbtProj / Test / fullClasspathAsJars).value
       .map(_.data)
+      .map(converter.toPath)
+      .map(_.toFile)
       .filterNot(_.getName.contains("scala-compiler")),
-    (bundledLauncherProj / Compile / packageBin).value,
+    converter.toPath((bundledLauncherProj / Compile / packageBin).value).toFile,
     streams.value.log,
-    scriptedKeepTempDirectory.value,
+    local.LocalScriptedPlugin.autoImport.scriptedKeepTempDirectory.value,
     (scripted / includeFilter).value,
     (scripted / excludeFilter).value,
   )
@@ -1089,7 +1098,7 @@ lazy val nonRoots = allProjects.map(p => LocalProject(p.id))
 
 ThisBuild / scriptedBufferLog := true
 ThisBuild / scriptedPrescripted := { _ => }
-ThisBuild / scriptedKeepTempDirectory := false
+ThisBuild / local.LocalScriptedPlugin.autoImport.scriptedKeepTempDirectory := false
 
 def otherRootSettings =
   Seq(
@@ -1231,6 +1240,7 @@ lazy val lmIvy = (project in file("lm-ivy"))
   .enablePlugins(ContrabandPlugin, JsonCodecPlugin)
   .dependsOn(lmCore)
   .settings(
+    exportJars := false,
     commonSettings,
     lmTestSettings,
     name := "librarymanagement-ivy",
@@ -1314,6 +1324,7 @@ lazy val lmCoursier = project
 lazy val lmCoursierShaded = project
   .in(file("lm-coursier/target/shaded-module"))
   .settings(
+    exportJars := false,
     lmCoursierSettings,
     Mima.settings,
     Mima.lmCoursierFilters,
@@ -1410,13 +1421,15 @@ lazy val launcherPackageIntegrationTest =
       Test / fork := true,
       Test / javaOptions += {
         val cp = (Test / fullClasspath).value
-          .map(_.data.getAbsolutePath)
+          .map(_.data)
+          .map(fileConverter.value.toPath)
+          .map(_.toFile.getAbsolutePath)
           .mkString(java.io.File.pathSeparator)
         s"-Dsbt.test.classpath=$cp"
       },
       Test / javaOptions += s"-Dsbt.test.integrationtest.basedir=${(baseDirectory).value.getAbsolutePath}",
-      Test / test := {
-        (Test / test)
+      Test / testFull := Def.uncached {
+        (Test / testFull)
           .dependsOn(launcherPackage / Universal / packageBin)
           .dependsOn(launcherPackage / Universal / stage)
           .value

launcher-package/build.sbt

@@ -54,9 +54,10 @@ lazy val isWindows: Boolean =
 lazy val isExperimental = sbtVersionToRelease.contains("RC") || sbtVersionToRelease.contains("M")
 val sbtLaunchJarUrl = SettingKey[String]("sbt-launch-jar-url")
 val sbtLaunchJarLocation = SettingKey[File]("sbt-launch-jar-location")
-val sbtLaunchJar = TaskKey[File]("sbt-launch-jar", "Resolves SBT launch jar")
+val sbtLaunchJar = TaskKey[HashedVirtualFileRef]("sbt-launch-jar", "Resolves SBT launch jar")
 val moduleID = (organization) apply { (o) => ModuleID(o, "sbt", sbtVersionToRelease) }
-val sbtnJarsMappings = TaskKey[Seq[(File, String)]]("sbtn-jars-mappings", "Resolves sbtn JARs")
+val sbtnJarsMappings =
+  TaskKey[Seq[(HashedVirtualFileRef, String)]]("sbtn-jars-mappings", "Resolves sbtn JARs")
 val sbtnJarsBaseUrl = SettingKey[String]("sbtn-jars-base-url")
 
 lazy val bintrayDebianUrl = settingKey[String]("API point for Debian packages")
@@ -76,8 +77,10 @@ val bintrayReleaseAllStaged =
 val windowsBuildId = settingKey[Int]("build id for Windows installer")
 val debianBuildId = settingKey[Int]("build id for Debian")
 
+@transient
 val exportRepoUsingCoursier = taskKey[File]("export Maven style repository")
 val exportRepoCsrDirectory = settingKey[File]("")
+@transient
 val exportRepo = taskKey[File]("export Ivy style repository")
 val exportRepoDirectory = settingKey[File]("directory for exported repository")
 
@@ -107,7 +110,7 @@ val launcherPackage = (project in file("."))
   .settings(
     name := "sbt-launcher-packaging",
     packageName := "sbt",
-    crossTarget := target.value,
+    crossPaths := false,
     autoScalaLibrary := false,
     clean := {
       val _ = (dist / clean).value
@@ -142,7 +145,7 @@ val launcherPackage = (project in file("."))
         }
       }
       // TODO - GPG Trust validation.
-      file
+      fileConverter.value.toVirtualFile(file.toPath)
     },
     sbtnJarsBaseUrl := "https://github.com/sbt/sbtn-dist/releases/download",
     sbtnJarsMappings := {
@@ -226,14 +229,20 @@ val launcherPackage = (project in file("."))
         IO.move(platformDir / "sbtn.exe", t / x86WindowsImageName)
       }
       if (!sbtIncludeSbtn) Seq()
-      else if (isWindows) Seq(t / x86WindowsImageName -> s"bin/$x86WindowsImageName")
+      else if (isWindows)
+        Seq(
+          fileConverter.value
+            .toVirtualFile((t / x86WindowsImageName).toPath) -> s"bin/$x86WindowsImageName"
+        )
       else
         Seq(
           t / universalMacImageName -> s"bin/$universalMacImageName",
           t / x86LinuxImageName -> s"bin/$x86LinuxImageName",
           t / aarch64LinuxImageName -> s"bin/$aarch64LinuxImageName",
           t / x86WindowsImageName -> s"bin/$x86WindowsImageName"
-        )
+        ).map { (k, v) =>
+          fileConverter.value.toVirtualFile(k.toPath) -> v
+        }
     },
 
     // GENERAL LINUX PACKAGING STUFFS
@@ -332,7 +341,9 @@ val launcherPackage = (project in file("."))
     Windows / packageName := packageName.value,
     Universal / version := sbtVersionToRelease,
     Universal / mappings += {
-      (baseDirectory.value.getParentFile / "sbt") -> ("bin" + java.io.File.separator + "sbt")
+      fileConverter.value.toVirtualFile(
+        (baseDirectory.value.getParentFile / "sbt").toPath
+      ) -> ("bin" + java.io.File.separator + "sbt")
     },
     Universal / mappings := {
       val t = (Universal / target).value
@@ -342,7 +353,7 @@ val launcherPackage = (project in file("."))
       prev.toList map {
         case (k, BinSbt) =>
           import java.nio.file.{ Files, FileSystems }
-          val x = IO.read(k)
+          val x = IO.read(fileConverter.value.toPath(k).toFile)
           IO.write(
             t / "sbt",
             x.replace(
@@ -352,13 +363,13 @@ val launcherPackage = (project in file("."))
           )
 
           if (FileSystems.getDefault.supportedFileAttributeViews.contains("posix")) {
-            val perms = Files.getPosixFilePermissions(k.toPath)
+            val perms = Files.getPosixFilePermissions(fileConverter.value.toPath(k))
             Files.setPosixFilePermissions((t / "sbt").toPath, perms)
           }
 
-          (t / "sbt", BinSbt)
+          (fileConverter.value.toVirtualFile((t / "sbt").toPath), BinSbt)
         case (k, BinBat) =>
-          val x = IO.read(k)
+          val x = IO.read(fileConverter.value.toPath(k).toFile)
           IO.write(
             t / "sbt.bat",
             x.replace(
@@ -366,7 +377,7 @@ val launcherPackage = (project in file("."))
               s"set init_sbt_version=$sbtVersionToRelease"
             )
           )
-          (t / "sbt.bat", BinBat)
+          (fileConverter.value.toVirtualFile((t / "sbt.bat").toPath), BinBat)
         case (k, v) => (k, v)
       }
     },
@@ -377,29 +388,34 @@ val launcherPackage = (project in file("."))
             sbtLaunchJar.value -> "bin/sbt-launch.jar"
           )
         }
-      else Def.task { Seq[(File, String)]() }
+      else Def.task { Seq[(HashedVirtualFileRef, String)]() }
     }).value,
     Universal / mappings ++= sbtnJarsMappings.value,
     Universal / mappings ++= (Def.taskDyn {
       if (sbtOfflineInstall && sbtVersionToRelease.startsWith("1."))
         Def.task {
           val _ = ((dist / exportRepoUsingCoursier)).value
-          directory(((dist / target)).value / "lib")
+          directory(((dist / target)).value / "lib").map { (k, v) =>
+            fileConverter.value.toVirtualFile(k.toPath) -> v
+          }
         }
       else if (sbtOfflineInstall)
         Def.task {
           val _ = ((dist / exportRepo)).value
-          directory(((dist / target)).value / "lib")
+          directory(((dist / target)).value / "lib").map { (k, v) =>
+            fileConverter.value.toVirtualFile(k.toPath) -> v
+          }
         }
-      else Def.task { Seq[(File, String)]() }
+      else Def.task { Seq[(HashedVirtualFileRef, String)]() }
     }).value,
     Universal / mappings ++= {
       val base = baseDirectory.value
+      val converter = fileConverter.value
       if (sbtVersionToRelease.startsWith("0.13.")) Nil
       else
-        Seq[(File, String)](
-          base.getParentFile / "LICENSE" -> "LICENSE",
-          base / "NOTICE" -> "NOTICE"
+        Seq[(HashedVirtualFileRef, String)](
+          converter.toVirtualFile((base.getParentFile / "LICENSE").toPath) -> "LICENSE",
+          converter.toVirtualFile((base / "NOTICE").toPath) -> "NOTICE"
         )
     },
 
@@ -458,7 +474,7 @@ def makePublishToForConfig(config: Configuration) = {
       },
       publishTo := {
         val (id, url, pattern) = bintrayTripple.value
-        val resolver = Resolver.url(id, new URI(url).toURL)(Patterns(pattern))
+        val resolver = Resolver.url(id, new URI(url).toURL)(using Patterns(pattern))
         Some(resolver)
       }
     )

launcher-package/integration-test/src/test/scala/ExtendedRunnerTest.scala

@@ -84,11 +84,11 @@ object ExtendedRunnerTest extends BasicTestSuite:
       "compile",
       "-v",
       "--sbt-jar",
-      "../target/universal/stage/bin/sbt-launch.jar"
+      "../../target/out/jvm/u/sbt-launcher-packaging/universal/stage/bin/sbt-launcher.jar"
     ).!!.linesIterator.toList
     assert(
-      out.contains[String]("../target/universal/stage/bin/sbt-launch.jar") ||
-        out.contains[String]("\"../target/universal/stage/bin/sbt-launch.jar\"")
+      out.contains[String]("../../target/out/jvm/u/sbt-launcher-packaging/universal/stage/bin/sbt-launcher.jar") ||
+        out.contains[String]("\"../../target/out/jvm/u/sbt-launcher-packaging/universal/stage/bin/sbt-launcher.jar\"")
     )
     ()
   }

launcher-package/integration-test/src/test/scala/IntegrationTestPaths.scala

@@ -16,11 +16,11 @@ object IntegrationTestPaths {
     baseDir match {
       case Some(b) =>
         val name = if (isWindows) "sbt.bat" else "sbt"
-        new File(b.getParentFile, s"target/universal/stage/bin/$name").getAbsoluteFile
+        new File(b.getParentFile.getParentFile, s"target/out/jvm/u/sbt-launcher-packaging/universal/stage/bin/$name").getAbsoluteFile
       case None =>
         val rel =
-          if (isWindows) "../target/universal/stage/bin/sbt.bat"
-          else "../target/universal/stage/bin/sbt"
+          if (isWindows) "../../target/out/jvm/u/sbt-launcher-packaging/universal/stage/bin/sbt.bat"
+          else "../../target/out/jvm/u/sbt-launcher-packaging/universal/stage/bin/sbt"
         new File(rel).getAbsoluteFile
     }
 

project/HouseRulesPlugin.scala

@@ -1,5 +1,6 @@
 import sbt.*
 import Keys.*
+import sbt.util.CacheImplicits.given
 
 object HouseRulesPlugin extends AutoPlugin {
   override def requires = plugins.JvmPlugin

project/PackageSignerPlugin.scala

@@ -1,5 +1,6 @@
 import sbt.*
 import Keys.*
+import sbt.util.CacheImplicits.given
 import sbt.internal.librarymanagement.IvyActions
 import com.jsuereth.sbtpgp.SbtPgp
 import com.typesafe.sbt.packager.universal.{ UniversalPlugin, UniversalDeployPlugin }
@@ -25,28 +26,34 @@ object PackageSignerPlugin extends sbt.AutoPlugin {
     art.withExtension(ext)
 
   def packageSignerSettings: Seq[Setting[?]] = Seq(
-    signedArtifacts := {
+    signedArtifacts := Def.uncached {
       val artifacts = packagedArtifacts.value
       val r = pgpSigner.value
       val skipZ = (pgpSigner / skip).value
       val s = streams.value
+      val converter = fileConverter.value
       if (!skipZ) {
-        artifacts flatMap { case (art, f) =>
+        artifacts flatMap { case (art, virtualFile) =>
+          val f = converter.toPath(virtualFile).toFile
           Seq(
-            art -> f,
+            art -> virtualFile,
             subExtension(art, art.extension + gpgExtension) ->
-              r.sign(f, file(f.getAbsolutePath + gpgExtension), s)
+              converter.toVirtualFile(r.sign(f, file(f.getAbsolutePath + gpgExtension), s).toPath)
           )
         }
       } else artifacts
     },
     publishSignedConfiguration := Classpaths.publishConfig(
       publishMavenStyle = publishMavenStyle.value,
-      deliverIvyPattern =
-        (Compile / packageBin / artifactPath).value.getParent + "/[artifact]-[revision](-[classifier]).[ext]",
+      deliverIvyPattern = fileConverter.value
+        .toPath((Compile / packageBin / artifactPath).value)
+        .toFile
+        .getParent + "/[artifact]-[revision](-[classifier]).[ext]",
       status = if (isSnapshot.value) "integration" else "release",
       configurations = Vector.empty,
-      artifacts = signedArtifacts.value.toVector,
+      artifacts = signedArtifacts.value.map { (k, v) =>
+        k -> fileConverter.value.toPath(v).toFile
+      }.toVector,
       checksums = (publish / checksums).value.toVector,
       resolverName = Classpaths.getPublishTo(publishTo.value).name,
       logging = ivyLoggingLevel.value,
@@ -54,11 +61,15 @@ object PackageSignerPlugin extends sbt.AutoPlugin {
     ),
     publishLocalSignedConfiguration := Classpaths.publishConfig(
       publishMavenStyle = publishMavenStyle.value,
-      deliverIvyPattern =
-        (Compile / packageBin / artifactPath).value.getParent + "/[artifact]-[revision](-[classifier]).[ext]",
+      deliverIvyPattern = fileConverter.value
+        .toPath((Compile / packageBin / artifactPath).value)
+        .toFile
+        .getParent + "/[artifact]-[revision](-[classifier]).[ext]",
       status = if (isSnapshot.value) "integration" else "release",
       configurations = Vector.empty,
-      artifacts = signedArtifacts.value.toVector,
+      artifacts = signedArtifacts.value.map { (k, v) =>
+        k -> fileConverter.value.toPath(v).toFile
+      }.toVector,
       checksums = (publish / checksums).value.toVector,
       resolverName = "local",
       logging = ivyLoggingLevel.value,

project/PublishBinPlugin.scala

@@ -3,6 +3,7 @@ package sbt
 import java.nio.file.{ FileAlreadyExistsException, Files }
 
 import sbt.Keys.*
+import sbt.util.CacheImplicits.given
 import sbt.internal.librarymanagement.IvyXml
 
 /** This local plugin provides ways of publishing just the binary jar. */
@@ -15,48 +16,57 @@ object PublishBinPlugin extends AutoPlugin {
   }
   import autoImport.*
 
-  private val dummyDoc = taskKey[File]("").withRank(Int.MaxValue)
+  private val dummyDoc = taskKey[HashedVirtualFileRef]("").withRank(Int.MaxValue)
   override val globalSettings = Seq(publishLocalBin := (()))
 
   override val projectSettings: Seq[Def.Setting[?]] = Def.settings(
     publishLocalBin := Classpaths
       .publishOrSkip(publishLocalBinConfig, publishLocalBin / skip)
       .value,
-    publishLocalBinConfig := Classpaths.publishConfig(
-      false, // publishMavenStyle.value,
-      Classpaths.deliverPattern(crossTarget.value),
-      if (isSnapshot.value) "integration" else "release",
-      ivyConfigurations.value.map(c => ConfigRef(c.name)).toVector,
-      (publishLocalBin / packagedArtifacts).value.toVector,
-      (publishLocalBin / checksums).value.toVector,
-      logging = ivyLoggingLevel.value,
-      overwrite = isSnapshot.value
-    ),
-    publishLocalBinConfig := publishLocalBinConfig
-      .dependsOn(
-        // Copied from sbt.internal.
-        Def.task {
-          val currentProject = {
-            val proj = csrProject.value
-            val publications = csrPublications.value
-            proj.withPublications(publications)
-          }
-          IvyXml.writeFiles(currentProject, None, ivySbt.value, streams.value.log)
-        }
+    publishLocalBinConfig := Def.uncached(
+      Classpaths.publishConfig(
+        false, // publishMavenStyle.value,
+        Classpaths.deliverPattern(crossTarget.value),
+        if (isSnapshot.value) "integration" else "release",
+        ivyConfigurations.value.map(c => ConfigRef(c.name)).toVector,
+        (publishLocalBin / packagedArtifacts).value.map { (k, v) =>
+          k -> fileConverter.value.toPath(v).toFile
+        }.toVector,
+        (publishLocalBin / checksums).value.toVector,
+        logging = ivyLoggingLevel.value,
+        overwrite = isSnapshot.value
       )
-      .value,
+    ),
+    publishLocalBinConfig := Def.uncached(
+      publishLocalBinConfig
+        .dependsOn(
+          // Copied from sbt.internal.
+          Def.task {
+            val currentProject = {
+              val proj = csrProject.value
+              val publications = csrPublications.value
+              proj.withPublications(publications)
+            }
+            IvyXml.writeFiles(currentProject, None, ivySbt.value, streams.value.log, Nil)
+          }
+        )
+        .value
+    ),
     dummyDoc := {
       val dummyFile = streams.value.cacheDirectory / "doc.jar"
       try {
         Files.createDirectories(dummyFile.toPath.getParent)
         Files.createFile(dummyFile.toPath)
       } catch { case _: FileAlreadyExistsException => }
-      dummyFile
+      fileConverter.value.toVirtualFile(dummyFile.toPath)
     },
-    dummyDoc / packagedArtifact := (Compile / packageDoc / artifact).value -> dummyDoc.value,
-    publishLocalBin / packagedArtifacts :=
+    dummyDoc / packagedArtifact := Def.uncached(
+      (Compile / packageDoc / artifact).value -> dummyDoc.value
+    ),
+    publishLocalBin / packagedArtifacts := Def.uncached(
       Classpaths
         .packaged(Seq(Compile / packageBin, Compile / packageSrc, makePom, dummyDoc))
         .value
+    )
   )
 }

project/SbtLauncherPlugin.scala

@@ -1,23 +1,30 @@
 import sbt.Keys.*
 import sbt.*
 import sbt.io.CopyOptions
+import sbt.util.CacheImplicits.given
 
 object SbtLauncherPlugin extends AutoPlugin {
   override def requires = plugins.IvyPlugin
 
   object autoImport {
     val SbtLaunchConfiguration = config("sbt-launch")
-    val sbtLaunchJar = taskKey[File]("constructs an sbt-launch.jar for this version of sbt.")
+    val sbtLaunchJar =
+      taskKey[HashedVirtualFileRef]("constructs an sbt-launch.jar for this version of sbt.")
     val rawSbtLaunchJar =
-      taskKey[File]("The released version of the sbt-launcher we use to bundle this application.")
+      taskKey[HashedVirtualFileRef](
+        "The released version of the sbt-launcher we use to bundle this application."
+      )
   }
   import autoImport.*
 
   override def projectConfigurations: Seq[Configuration] = Seq(SbtLaunchConfiguration)
   override def projectSettings: Seq[Setting[?]] = Seq(
     libraryDependencies += Dependencies.rawLauncher % SbtLaunchConfiguration.name,
-    rawSbtLaunchJar := {
-      Classpaths.managedJars(SbtLaunchConfiguration, Set("jar"), update.value).headOption match {
+    rawSbtLaunchJar := Def.uncached {
+      val converter = fileConverter.value
+      Classpaths
+        .managedJars(SbtLaunchConfiguration, Set("jar"), update.value, converter)
+        .headOption match {
         case Some(jar) => jar.data
         case None =>
           sys.error(
@@ -25,7 +32,7 @@ object SbtLauncherPlugin extends AutoPlugin {
           )
       }
     },
-    sbtLaunchJar := {
+    sbtLaunchJar := Def.uncached {
       val propFiles = (Compile / resources).value
       val propFileLocations =
         for (file <- propFiles; if file.getName != "resources") yield {
@@ -33,7 +40,13 @@ object SbtLauncherPlugin extends AutoPlugin {
           else file.getName -> file
         }
       // TODO - We need to inject the appropriate boot.properties file for this version of sbt.
-      rebundle(rawSbtLaunchJar.value, propFileLocations.toMap, target.value / "sbt-launch.jar")
+      fileConverter.value.toVirtualFile(
+        rebundle(
+          fileConverter.value.toPath(rawSbtLaunchJar.value).toFile,
+          propFileLocations.toMap,
+          target.value / "sbt-launch.jar"
+        ).toPath
+      )
     }
   )
 

project/Scripted.scala

@@ -6,7 +6,7 @@ import sbt.*
 import sbt.internal.inc.ScalaInstance
 import sbt.internal.inc.classpath.{ ClasspathUtilities, FilteredLoader }
 import scala.annotation.nowarn
-import scala.collection.JavaConverters.*
+import scala.jdk.CollectionConverters.*
 
 object LocalScriptedPlugin extends AutoPlugin {
   override def requires = plugins.JvmPlugin
@@ -21,6 +21,7 @@ trait ScriptedKeys {
       "Saves you some time when only your test has changed"
   )
   val scriptedSource = settingKey[File]("")
+  @transient
   val scriptedPrescripted = taskKey[File => Unit]("")
   val scriptedKeepTempDirectory = settingKey[Boolean](
     "If true, keeps the temporary directory after scripted tests complete for debugging."
@@ -63,10 +64,10 @@ object Scripted {
         val p = f.getParentFile
         (p.getParentFile.getName, p.getName)
     }
-    val pairMap = pairs.groupBy(_._1).mapValues(_.map(_._2).toSet)
+    val pairMap = pairs.groupBy(_._1).view.mapValues(_.map(_._2).toSet).toMap
 
     val id = charClass(c => !c.isWhitespace && c != '/').+.string
-    val groupP = token(id.examples(pairMap.keySet)) <~ token('/')
+    val groupP = token(id.examples(pairMap.keySet.toSet)) <~ token('/')
 
     // A parser for page definitions
     val pageNumber = (NatBasic & not('0', "zero page number")).flatMap { i =>
@@ -128,9 +129,6 @@ object Scripted {
     logger.info(s"Tests selected: ${args.mkString("\n * ", "\n * ", "\n")}")
     logger.info("")
 
-    // Force Log4J to not use a thread context classloader otherwise it throws a CCE
-    sys.props(org.apache.logging.log4j.util.LoaderUtil.IGNORE_TCCL_PROPERTY) = "true"
-
     val noJLine = new FilteredLoader(scriptedSbtInstance.loader, "jline." :: Nil)
     val loader = ClasspathUtilities.toLoader(classpath, noJLine)
     val bridgeClass = Class.forName("sbt.scriptedtest.ScriptedRunner", true, loader)
@@ -171,7 +169,7 @@ object Scripted {
           case i if i > 0 => i
           case _          => 1
         }
-        import scala.language.reflectiveCalls
+        import scala.reflect.Selectable.reflectiveSelectable
 
         bridge.runInParallel(
           sourcePath,

project/Utils.scala

@@ -1,5 +1,7 @@
 import scala.util.control.NonFatal
 import sbt.*
+import sbt.given
+import sbt.util.CacheImplicits.given
 import Keys.*
 import scalafix.sbt.ScalafixPlugin.autoImport.scalafix
 
@@ -9,7 +11,9 @@ object Utils {
   val ExclusiveTest: Tags.Tag = Tags.Tag("exclusive-test")
 
   val componentID: SettingKey[Option[String]] = settingKey[Option[String]]("")
+  @transient
   val scalaKeywords: TaskKey[Set[String]] = taskKey[Set[String]]("")
+  @transient
   val generateKeywords: TaskKey[File] = taskKey[File]("")
   val sbtnVersion = SettingKey[String]("sbtn-version")
 
@@ -66,7 +70,7 @@ object Utils {
     IO.read(propFile).contains(versionLine(version))
 
   def publishPomSettings: Seq[Setting[?]] = Seq(
-    pomPostProcess := cleanPom _
+    pomPostProcess := cleanPom
   )
 
   def cleanPom(pomNode: scala.xml.Node) = {
@@ -100,12 +104,11 @@ object Utils {
   }
 
   def getScalaKeywords: Set[String] = {
-    val g = new scala.tools.nsc.Global(new scala.tools.nsc.Settings)
-    g.nme.keywords.map(_.toString)
+    dotty.tools.dotc.core.StdNames.nme.keywords.map(_.toString).toSet
   }
 
   def writeScalaKeywords(base: File, keywords: Set[String]): File = {
-    val init = keywords.map(tn => '"' + tn + '"').mkString("Set(", ", ", ")")
+    val init = keywords.map(tn => "\"" + tn + "\"").mkString("Set(", ", ", ")")
     val ObjectName = "ScalaKeywords"
     val PackageName = "sbt.internal.util"
     val keywordsSrc = s"""
@@ -123,7 +126,9 @@ object Utils {
     inConfig(Compile)(
       Seq(
         scalaKeywords := getScalaKeywords,
-        generateKeywords := writeScalaKeywords(sourceManaged.value, scalaKeywords.value),
+        generateKeywords := Def.uncached(
+          writeScalaKeywords(sourceManaged.value, scalaKeywords.value)
+        ),
         sourceGenerators += Def.task(Seq(generateKeywords.value)).taskValue
       )
     )
@@ -145,6 +150,7 @@ object Utils {
 
 object Licensed {
   lazy val notice = SettingKey[Option[File]]("notice")
+  @transient
   lazy val extractLicenses = TaskKey[Seq[File]]("extract-licenses")
 
   lazy val seeRegex = """\(see (.*?)\)""".r

project/build.properties

@@ -1 +1 @@
-sbt.version=1.12.10
+sbt.version=2.0.0-RC13

project/plugins.sbt

@@ -1,5 +1,5 @@
 Global / semanticdbVersion := "4.15.2"
-scalacOptions ++= Seq("-feature", "-Ywarn-unused:_,-imports")
+scalacOptions ++= Seq("-feature", "-language:implicitConversions")
 
 addSbtPlugin("com.github.sbt" % "sbt-dynver" % "5.1.1")
 addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.3.1")

sbt-app/src/sbt-test/ivy/build-deps/project/plugins.sbt

@@ -1,4 +1,5 @@
-libraryDependencies += {
-  val sbtV = sbtVersion.value
-  ("org.scala-sbt" % s"sbt-ivy_sbt${sbtV}_${scalaBinaryVersion.value}" % sbtV).intransitive()
-}
+libraryDependencies += Defaults.sbtPluginExtra(
+  "org.scala-sbt" % "sbt-ivy" % sbtVersion.value,
+  sbtVersion.value,
+  scalaVersion.value,
+)

sbt-app/src/sbt-test/ivy/deliver-artifacts/project/plugins.sbt

@@ -1,4 +1,5 @@
-libraryDependencies += {
-  val sbtV = sbtVersion.value
-  ("org.scala-sbt" % s"sbt-ivy_sbt${sbtV}_${scalaBinaryVersion.value}" % sbtV).intransitive()
-}
+libraryDependencies += Defaults.sbtPluginExtra(
+  "org.scala-sbt" % "sbt-ivy" % sbtVersion.value,
+  sbtVersion.value,
+  scalaVersion.value,
+)

sbt-app/src/sbt-test/ivy/exclude-dependencies/project/plugins.sbt

@@ -1,4 +1,5 @@
-libraryDependencies += {
-  val sbtV = sbtVersion.value
-  ("org.scala-sbt" % s"sbt-ivy_sbt${sbtV}_${scalaBinaryVersion.value}" % sbtV).intransitive()
-}
+libraryDependencies += Defaults.sbtPluginExtra(
+  "org.scala-sbt" % "sbt-ivy" % sbtVersion.value,
+  sbtVersion.value,
+  scalaVersion.value,
+)

sbt-app/src/sbt-test/ivy/make-ivy-xml/project/plugins.sbt

@@ -1,4 +1,5 @@
-libraryDependencies += {
-  val sbtV = sbtVersion.value
-  ("org.scala-sbt" % s"sbt-ivy_sbt${sbtV}_${scalaBinaryVersion.value}" % sbtV).intransitive()
-}
+libraryDependencies += Defaults.sbtPluginExtra(
+  "org.scala-sbt" % "sbt-ivy" % sbtVersion.value,
+  sbtVersion.value,
+  scalaVersion.value,
+)

sbt-app/src/sbt-test/ivy/provided-multi/project/plugins.sbt

@@ -1,4 +1,5 @@
-libraryDependencies += {
-  val sbtV = sbtVersion.value
-  ("org.scala-sbt" % s"sbt-ivy_sbt${sbtV}_${scalaBinaryVersion.value}" % sbtV).intransitive()
-}
+libraryDependencies += Defaults.sbtPluginExtra(
+  "org.scala-sbt" % "sbt-ivy" % sbtVersion.value,
+  sbtVersion.value,
+  scalaVersion.value,
+)

scripts/lm-coursier-ci.sh

@@ -19,7 +19,7 @@ else
 fi
 
 # publishing locally to ensure shading runs fine
-./lm-coursier/metadata/scripts/with-test-repo.sh $SBT \
+./lm-coursier/metadata/scripts/with-test-repo.sh $SBT --server \
   lmCoursierShadedPublishing/publishLocal \
   lmCoursier/test \
   'scripted lm-coursier/*'