diff --git a/.github/workflows/client-test.yml b/.github/workflows/client-test.yml
index ea752c5a7..65c286adc 100644
--- a/.github/workflows/client-test.yml
+++ b/.github/workflows/client-test.yml
@@ -58,10 +58,9 @@ jobs:
         ./client/target/bin/sbtn --sbt-script=$(pwd)/sbt shutdown
         # test launcher script
         echo build using JDK 8 test using JDK 8 and JDK 25
-        cd launcher-package
-        sbt -Dsbt.build.version=$TEST_SBT_VER rpm:packageBin debian:packageBin
-        sbt -Dsbt.build.version=$TEST_SBT_VER integrationTest/test
-        cd citest && ./test.sh
+        sbt -Dsbt.build.version=$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"
         PATH="$JAVA_HOME_25_X64/bin:$PATH"
         java -Xmx32m -version
@@ -73,11 +72,10 @@ jobs:
         # test building sbtn on macOS
         ./sbt "-Dsbt.io.virtual=false" nativeImage
         # test launcher script
-        cd launcher-package
-        bin/coursier resolve
-        sbt -Dsbt.build.version=$TEST_SBT_VER integrationTest/test
+        launcher-package/bin/coursier resolve
+        sbt -Dsbt.build.version=$TEST_SBT_VER launcherPackageIntegrationTest/test
         # This fails due to the JLine issue
-        # cd citest && ./test.sh
+        # cd launcher-package/citest && ./test.sh
     - name: build image (Windows)
       if: ${{ matrix.os == 'windows-latest' }}
       uses: nick-fields/retry@ce71cc2ab81d554ebbe88c79ab5975992d79ba08 # v3.0.2
@@ -97,9 +95,8 @@ jobs:
         ./client/target/bin/sbtn --sbt-script=$(pwd)/launcher-package/src/universal/bin/sbt.bat shutdown
         # test launcher script
         echo build using JDK 8 test using JDK 8 and JDK 25
-        cd launcher-package
-        bin/coursier.bat resolve
-        sbt -Dsbt.build.version=$TEST_SBT_VER integrationTest/test
-        cd citest
+        launcher-package/bin/coursier.bat resolve
+        sbt -Dsbt.build.version=$TEST_SBT_VER launcherPackageIntegrationTest/test
+        cd launcher-package/citest
         ./test.bat
         test3/test3.bat
diff --git a/build.sbt b/build.sbt
index 65caab2f4..b83ae8e18 100644
--- a/build.sbt
+++ b/build.sbt
@@ -53,6 +53,8 @@ Global / excludeLint := (Global / excludeLint).?.value.getOrElse(Set.empty)
 Global / excludeLint += Utils.componentID
 Global / excludeLint += scriptedBufferLog
 Global / excludeLint += checkPluginCross
+Global / excludeLint += nativeImageJvm
+Global / excludeLint += nativeImageVersion
 
 def commonSettings: Seq[Setting[?]] = Def.settings(
   headerLicense := Some(
@@ -1308,3 +1310,32 @@ lazy val lmCoursierShadedPublishing = project
     Compile / packageBin := (lmCoursierShaded / assembly).value,
     Compile / exportedProducts := Seq(Attributed.blank((Compile / packageBin).value))
   )
+
+lazy val launcherPackage = (project in file("launcher-package"))
+lazy val launcherPackageIntegrationTest =
+  (project in (file("launcher-package") / "integration-test"))
+    .settings(
+      name := "integration-test",
+      scalaVersion := scala3,
+      libraryDependencies ++= Seq(
+        scalaVerify % Test,
+        hedgehog % Test,
+        // This needs to be hardcoded here, and not use addSbtIO
+        "org.scala-sbt" %% "io" % "1.10.5" % Test,
+      ),
+      testFrameworks += TestFramework("hedgehog.sbt.Framework"),
+      testFrameworks += TestFramework("verify.runner.Framework"),
+      Test / test := {
+        (Test / test)
+          .dependsOn(launcherPackage / Universal / packageBin)
+          .dependsOn(launcherPackage / Universal / stage)
+          .value
+      },
+      Test / testOnly := {
+        (Test / testOnly)
+          .dependsOn(launcherPackage / Universal / packageBin)
+          .dependsOn(launcherPackage / Universal / stage)
+          .evaluated
+      },
+      Test / parallelExecution := false
+    )
diff --git a/launcher-package/build.sbt b/launcher-package/build.sbt
index 87b11b80b..cfd2ff49c 100755
--- a/launcher-package/build.sbt
+++ b/launcher-package/build.sbt
@@ -1,8 +1,9 @@
 import scala.util.control.Exception.catching
-import scala.sys.process._
-import NativePackagerHelper._
-import com.typesafe.sbt.packager.SettingsHelper._
-import DebianConstants._
+import scala.sys.process.*
+import NativePackagerHelper.*
+import com.typesafe.sbt.packager.SettingsHelper.*
+import DebianConstants.*
+import Dependencies.*
 
 lazy val sbtOfflineInstall =
   sys.props.getOrElse("sbt.build.offline", sys.env.getOrElse("sbt.build.offline", "false")) match {
@@ -22,12 +23,10 @@ lazy val sbtIncludeSbtLaunch =
     case "false" | "0" => false
     case _             => false
   }
-lazy val sbtVersionToRelease = sys.props.getOrElse("sbt.build.version", sys.env.getOrElse("sbt.build.version", {
-        sys.error("-Dsbt.build.version must be set")
-      }))
+lazy val sbtVersionToRelease = sys.props
+  .getOrElse("sbt.build.version", sys.env.getOrElse("sbt.build.version", "1.12.0"))
 
 lazy val scala210 = "2.10.7"
-lazy val scala212 = "2.12.21"
 lazy val scala210Jline = "org.scala-lang" % "jline" % scala210
 lazy val jansi = {
   if (sbtVersionToRelease startsWith "1.") "org.fusesource.jansi" % "jansi" % "1.12"
@@ -82,11 +81,10 @@ val x86LinuxImageName = s"sbtn-$x86LinuxPlatform"
 val aarch64LinuxImageName = s"sbtn-$aarch64LinuxPlatform"
 val x86WindowsImageName = s"sbtn-$x86WindowsPlatform.exe"
 
-ThisBuild / organization := "org.scala-sbt"
-ThisBuild / version := "0.1.0"
+Global / excludeLintKeys += bintrayGenericPackagesUrl
 
 // This build creates a SBT plugin with handy features *and* bundles the SBT script for distribution.
-val root = (project in file(".")).
+val launcherPackage = (project in file(".")).
   enablePlugins(UniversalPlugin, LinuxPlugin, DebianPlugin, RpmPlugin, WindowsPlugin,
     UniversalDeployPlugin, RpmDeployPlugin, WindowsDeployPlugin).
   settings(
@@ -289,16 +287,16 @@ val root = (project in file(".")).
       val stable = if (rpmRelease.value == "0") stable0
                    else stable0 + "." + rpmRelease.value
       if (isExperimental) ((sbtVersionToRelease split "[^\\d]" filterNot (_.isEmpty)).toList match {
-        case List(a, b, c, d) => List(0, 99, c, d).mkString(".")
+        case List(_, _, c, d) => List(0, 99, c, d).mkString(".")
       })
       else stable
     },
     // remove sbtn from RPM because it complains about it being noarch
     Rpm / linuxPackageMappings := {
       val orig = ((Rpm / linuxPackageMappings)).value
-      val nativeMappings = sbtnJarsMappings.value
+      val _ = sbtnJarsMappings.value
       orig.map(o => o.copy(mappings = o.mappings.toList filterNot {
-        case (x, p) => p.contains("sbtn-x86_64") || p.contains("sbtn-aarch64")
+        case (_, p) => p.contains("sbtn-x86_64") || p.contains("sbtn-aarch64")
       }))
     },
     rpmVendor := "scalacenter",
@@ -416,30 +414,6 @@ val root = (project in file(".")).
     }
   )
 
-lazy val integrationTest = (project in file("integration-test"))
-  .settings(
-    name := "integration-test",
-    scalaVersion := scala212,
-    libraryDependencies ++= Seq(
-      "io.monix" %% "minitest" % "2.3.2" % Test,
-      "com.eed3si9n.expecty" %% "expecty" % "0.11.0" % Test,
-      "org.scala-sbt" %% "io" % "1.10.5" % Test
-    ),
-    testFrameworks += new TestFramework("minitest.runner.Framework"),
-    Test / test := {
-      (Test / test)
-        .dependsOn(LocalRootProject / Universal / packageBin)
-        .dependsOn(LocalRootProject / Universal / stage).value
-    },
-    Test / testOnly := {
-      (Test / testOnly)
-        .dependsOn(LocalRootProject / Universal / packageBin)
-        .dependsOn(LocalRootProject / Universal / stage)
-        .evaluated
-    },
-    Test / parallelExecution := false
-  )
-
 def downloadUrlForVersion(v: String) = (v.split("[^\\d]") flatMap (i => catching(classOf[Exception]) opt (i.toInt))) match {
   case Array(0, 11, 3, _*)           => "https://repo.typesafe.com/typesafe/ivy-releases/org.scala-sbt/sbt-launch/0.11.3-2/sbt-launch.jar"
   case Array(0, 11, x, _*) if x >= 3 => "https://repo.typesafe.com/typesafe/ivy-releases/org.scala-sbt/sbt-launch/"+v+"/sbt-launch.jar"
@@ -449,8 +423,6 @@ def downloadUrlForVersion(v: String) = (v.split("[^\\d]") flatMap (i => catching
 }
 
 def makePublishToForConfig(config: Configuration) = {
-  val v = sbtVersionToRelease
-
   // Add the publish to and ensure global resolvers has the resolver we just configured.
   inConfig(config)(Seq(
     name := "sbt",
diff --git a/launcher-package/integration-test/src/test/scala/RunnerTest.scala b/launcher-package/integration-test/src/test/scala/ExtendedRunnerTest.scala
similarity index 75%
rename from launcher-package/integration-test/src/test/scala/RunnerTest.scala
rename to launcher-package/integration-test/src/test/scala/ExtendedRunnerTest.scala
index 7a9f38da8..1f4051277 100755
--- a/launcher-package/integration-test/src/test/scala/RunnerTest.scala
+++ b/launcher-package/integration-test/src/test/scala/ExtendedRunnerTest.scala
@@ -1,30 +1,36 @@
 package example.test
 
-import minitest._
-import scala.sys.process._
+import scala.sys.process.*
 import java.io.File
 import java.util.Locale
 import sbt.io.IO
+import verify.BasicTestSuite
 
-object SbtRunnerTest extends SimpleTestSuite with PowerAssertions {
+object ExtendedRunnerTest extends BasicTestSuite:
   // 1.3.0, 1.3.0-M4
   private[test] val versionRegEx = "\\d(\\.\\d+){2}(-\\w+)?"
 
   lazy val isWindows: Boolean = sys.props("os.name").toLowerCase(Locale.ENGLISH).contains("windows")
   lazy val isMac: Boolean = sys.props("os.name").toLowerCase(Locale.ENGLISH).contains("mac")
   lazy val sbtScript =
-    if (isWindows) new File("target/universal/stage/bin/sbt.bat")
-    else new File("target/universal/stage/bin/sbt")
+    if (isWindows) new File("launcher-package/target/universal/stage/bin/sbt.bat")
+    else new File("launcher-package/target/universal/stage/bin/sbt")
 
-  def sbtProcess(args: String*) = sbtProcessWithOpts(args: _*)("", "")
+  def sbtProcess(args: String*) = sbtProcessWithOpts(args*)("", "")
   def sbtProcessWithOpts(args: String*)(javaOpts: String, sbtOpts: String) =
-    sbt.internal.Process(Seq(sbtScript.getAbsolutePath) ++ args, new File("citest"),
+    Process(
+      Seq(sbtScript.getAbsolutePath) ++ args,
+      new File("launcher-package/citest"),
       "JAVA_OPTS" -> javaOpts,
-      "SBT_OPTS" -> sbtOpts)
+      "SBT_OPTS" -> sbtOpts
+    )
   def sbtProcessInDir(dir: File)(args: String*) =
-    sbt.internal.Process(Seq(sbtScript.getAbsolutePath) ++ args, dir,
+    Process(
+      Seq(sbtScript.getAbsolutePath) ++ args,
+      dir,
       "JAVA_OPTS" -> "",
-      "SBT_OPTS" -> "")
+      "SBT_OPTS" -> ""
+    )
 
   test("sbt runs") {
     assert(sbtScript.exists)
@@ -52,12 +58,12 @@ object SbtRunnerTest extends SimpleTestSuite with PowerAssertions {
     val out3 = sbtProcess("-V").!!.trim
     testVersion(out3.linesIterator.toList)
   }
-  */
+   */
 
   test("sbt -V in empty directory") {
     IO.withTemporaryDirectory { tmp =>
       val out = sbtProcessInDir(tmp)("-V").!!.trim
-      val expectedVersion = "^"+versionRegEx+"$"
+      val expectedVersion = "^" + versionRegEx + "$"
       val targetDir = new File(tmp, "target")
       assert(!targetDir.exists, "expected target directory to not exist, but existed")
     }
@@ -71,12 +77,18 @@ object SbtRunnerTest extends SimpleTestSuite with PowerAssertions {
     assert(out.matches(expectedVersion))
     ()
   }
-  */
+   */
 
   test("sbt --sbt-jar should run") {
-    val out = sbtProcess("compile", "-v", "--sbt-jar", "../target/universal/stage/bin/sbt-launch.jar").!!.linesIterator.toList
-    assert(out.contains[String]("../target/universal/stage/bin/sbt-launch.jar") ||
-      out.contains[String]("\"../target/universal/stage/bin/sbt-launch.jar\"")
+    val out = sbtProcess(
+      "compile",
+      "-v",
+      "--sbt-jar",
+      "../target/universal/stage/bin/sbt-launch.jar"
+    ).!!.linesIterator.toList
+    assert(
+      out.contains[String]("../target/universal/stage/bin/sbt-launch.jar") ||
+        out.contains[String]("\"../target/universal/stage/bin/sbt-launch.jar\"")
     )
     ()
   }
@@ -105,7 +117,7 @@ object SbtRunnerTest extends SimpleTestSuite with PowerAssertions {
   test("sbt --script-version in empty directory") {
     IO.withTemporaryDirectory { tmp =>
       val out = sbtProcessInDir(tmp)("--script-version").!!.trim
-      val expectedVersion = "^"+versionRegEx+"$"
+      val expectedVersion = "^" + versionRegEx + "$"
       assert(out.matches(expectedVersion))
     }
     ()
@@ -126,4 +138,4 @@ object SbtRunnerTest extends SimpleTestSuite with PowerAssertions {
     }
     ()
   }
-}
+end ExtendedRunnerTest
diff --git a/launcher-package/integration-test/src/test/scala/InheritInput.scala b/launcher-package/integration-test/src/test/scala/InheritInput.scala
deleted file mode 100644
index 6d150d881..000000000
--- a/launcher-package/integration-test/src/test/scala/InheritInput.scala
+++ /dev/null
@@ -1,17 +0,0 @@
-package sbt.internal
-
-import java.lang.{ ProcessBuilder => JProcessBuilder }
-
-private[sbt] object InheritInput {
-  def apply(p: JProcessBuilder): Boolean = (redirectInput, inherit) match {
-    case (Some(m), Some(f)) =>
-      m.invoke(p, f); true
-    case _ => false
-  }
-
-  private val pbClass = Class.forName("java.lang.ProcessBuilder")
-  private val redirectClass = pbClass.getClasses find (_.getSimpleName == "Redirect")
-
-  private val redirectInput = redirectClass map (pbClass.getMethod("redirectInput", _))
-  private val inherit = redirectClass map (_ getField "INHERIT" get null)
-}
diff --git a/launcher-package/integration-test/src/test/scala/PowerAssertions.scala b/launcher-package/integration-test/src/test/scala/PowerAssertions.scala
deleted file mode 100644
index eb3671b76..000000000
--- a/launcher-package/integration-test/src/test/scala/PowerAssertions.scala
+++ /dev/null
@@ -1,7 +0,0 @@
-package example.test
-
-import com.eed3si9n.expecty.Expecty
-
-trait PowerAssertions {
-  lazy val assert: Expecty = new Expecty()
-}
diff --git a/launcher-package/integration-test/src/test/scala/Process.scala b/launcher-package/integration-test/src/test/scala/Process.scala
deleted file mode 100644
index 40798e209..000000000
--- a/launcher-package/integration-test/src/test/scala/Process.scala
+++ /dev/null
@@ -1,216 +0,0 @@
-package sbt.internal
-
-import java.lang.{ Process => JProcess, ProcessBuilder => JProcessBuilder }
-import java.io.{ Closeable, File, IOException }
-import java.io.{ BufferedReader, InputStream, InputStreamReader, OutputStream, PipedInputStream, PipedOutputStream }
-import java.net.URL
-
-trait ProcessExtra {
-  import Process._
-  implicit def builderToProcess(builder: JProcessBuilder): ProcessBuilder = apply(builder)
-  implicit def fileToProcess(file: File): FilePartialBuilder = apply(file)
-  implicit def urlToProcess(url: URL): URLPartialBuilder = apply(url)
-
-  implicit def buildersToProcess[T](builders: Seq[T])(implicit convert: T => SourcePartialBuilder): Seq[SourcePartialBuilder] = applySeq(builders)
-
-  implicit def stringToProcess(command: String): ProcessBuilder = apply(command)
-  implicit def stringSeqToProcess(command: Seq[String]): ProcessBuilder = apply(command)
-}
-
-/** Methods for constructing simple commands that can then be combined. */
-object Process extends ProcessExtra {
-  def apply(command: String): ProcessBuilder = apply(command, None)
-
-  def apply(command: Seq[String]): ProcessBuilder = apply(command.toArray, None)
-
-  def apply(command: String, arguments: Seq[String]): ProcessBuilder = apply(command :: arguments.toList, None)
-  /** create ProcessBuilder with working dir set to File and extra environment variables */
-  def apply(command: String, cwd: File, extraEnv: (String, String)*): ProcessBuilder =
-    apply(command, Some(cwd), extraEnv: _*)
-  /** create ProcessBuilder with working dir set to File and extra environment variables */
-  def apply(command: Seq[String], cwd: File, extraEnv: (String, String)*): ProcessBuilder =
-    apply(command, Some(cwd), extraEnv: _*)
-  /** create ProcessBuilder with working dir optionally set to File and extra environment variables */
-  def apply(command: String, cwd: Option[File], extraEnv: (String, String)*): ProcessBuilder = {
-    apply(command.split("""\s+"""), cwd, extraEnv: _*)
-    // not smart to use this on windows, because CommandParser uses \ to escape ".
-    /*CommandParser.parse(command) match {
-      case Left(errorMsg) => error(errorMsg)
-      case Right((cmd, args)) => apply(cmd :: args, cwd, extraEnv : _*)
-    }*/
-  }
-  /** create ProcessBuilder with working dir optionally set to File and extra environment variables */
-  def apply(command: Seq[String], cwd: Option[File], extraEnv: (String, String)*): ProcessBuilder = {
-    val jpb = new JProcessBuilder(command.toArray: _*)
-    cwd.foreach(jpb directory _)
-    extraEnv.foreach { case (k, v) => jpb.environment.put(k, v) }
-    apply(jpb)
-  }
-  def apply(builder: JProcessBuilder): ProcessBuilder = new SimpleProcessBuilder(builder)
-  def apply(file: File): FilePartialBuilder = new FileBuilder(file)
-  def apply(url: URL): URLPartialBuilder = new URLBuilder(url)
-
-  def applySeq[T](builders: Seq[T])(implicit convert: T => SourcePartialBuilder): Seq[SourcePartialBuilder] = builders.map(convert)
-
-  def apply(value: Boolean): ProcessBuilder = apply(value.toString, if (value) 0 else 1)
-  def apply(name: String, exitValue: => Int): ProcessBuilder = new DummyProcessBuilder(name, exitValue)
-
-  def cat(file: SourcePartialBuilder, files: SourcePartialBuilder*): ProcessBuilder = cat(file :: files.toList)
-  def cat(files: Seq[SourcePartialBuilder]): ProcessBuilder =
-    {
-      require(files.nonEmpty)
-      files.map(_.cat).reduceLeft(_ #&& _)
-    }
-}
-
-trait SourcePartialBuilder extends NotNull {
-  /** Writes the output stream of this process to the given file. */
-  def #>(f: File): ProcessBuilder = toFile(f, false)
-  /** Appends the output stream of this process to the given file. */
-  def #>>(f: File): ProcessBuilder = toFile(f, true)
-  /**
-   * Writes the output stream of this process to the given OutputStream. The
-   * argument is call-by-name, so the stream is recreated, written, and closed each
-   * time this process is executed.
-   */
-  def #>(out: => OutputStream): ProcessBuilder = #>(new OutputStreamBuilder(out))
-  def #>(b: ProcessBuilder): ProcessBuilder = new PipedProcessBuilder(toSource, b, false, ExitCodes.firstIfNonzero)
-  private def toFile(f: File, append: Boolean) = #>(new FileOutput(f, append))
-  def cat = toSource
-  protected def toSource: ProcessBuilder
-}
-trait SinkPartialBuilder extends NotNull {
-  /** Reads the given file into the input stream of this process. */
-  def #<(f: File): ProcessBuilder = #<(new FileInput(f))
-  /** Reads the given URL into the input stream of this process. */
-  def #<(f: URL): ProcessBuilder = #<(new URLInput(f))
-  /**
-   * Reads the given InputStream into the input stream of this process. The
-   * argument is call-by-name, so the stream is recreated, read, and closed each
-   * time this process is executed.
-   */
-  def #<(in: => InputStream): ProcessBuilder = #<(new InputStreamBuilder(in))
-  def #<(b: ProcessBuilder): ProcessBuilder = new PipedProcessBuilder(b, toSink, false, ExitCodes.firstIfNonzero)
-  protected def toSink: ProcessBuilder
-}
-
-trait URLPartialBuilder extends SourcePartialBuilder
-trait FilePartialBuilder extends SinkPartialBuilder with SourcePartialBuilder {
-  def #<<(f: File): ProcessBuilder
-  def #<<(u: URL): ProcessBuilder
-  def #<<(i: => InputStream): ProcessBuilder
-  def #<<(p: ProcessBuilder): ProcessBuilder
-}
-
-/**
- * Represents a process that is running or has finished running.
- * It may be a compound process with several underlying native processes (such as 'a #&& b`).
- */
-trait Process extends NotNull {
-  /** Blocks until this process exits and returns the exit code.*/
-  def exitValue(): Int
-  /** Destroys this process. */
-  def destroy(): Unit
-}
-/** Represents a runnable process. */
-trait ProcessBuilder extends SourcePartialBuilder with SinkPartialBuilder {
-  /**
-   * Starts the process represented by this builder, blocks until it exits, and returns the output as a String.  Standard error is
-   * sent to the console.  If the exit code is non-zero, an exception is thrown.
-   */
-  def !! : String
-  /**
-   * Starts the process represented by this builder, blocks until it exits, and returns the output as a String.  Standard error is
-   * sent to the provided ProcessLogger.  If the exit code is non-zero, an exception is thrown.
-   */
-  def !!(log: ProcessLogger): String
-  /**
-   * Starts the process represented by this builder.  The output is returned as a Stream that blocks when lines are not available
-   * but the process has not completed.  Standard error is sent to the console.  If the process exits with a non-zero value,
-   * the Stream will provide all lines up to termination and then throw an exception.
-   */
-  def lines: Stream[String]
-  /**
-   * Starts the process represented by this builder.  The output is returned as a Stream that blocks when lines are not available
-   * but the process has not completed.  Standard error is sent to the provided ProcessLogger.  If the process exits with a non-zero value,
-   * the Stream will provide all lines up to termination but will not throw an exception.
-   */
-  def lines(log: ProcessLogger): Stream[String]
-  /**
-   * Starts the process represented by this builder.  The output is returned as a Stream that blocks when lines are not available
-   * but the process has not completed.  Standard error is sent to the console. If the process exits with a non-zero value,
-   * the Stream will provide all lines up to termination but will not throw an exception.
-   */
-  def lines_! : Stream[String]
-  /**
-   * Starts the process represented by this builder.  The output is returned as a Stream that blocks when lines are not available
-   * but the process has not completed.  Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value,
-   * the Stream will provide all lines up to termination but will not throw an exception.
-   */
-  def lines_!(log: ProcessLogger): Stream[String]
-  /**
-   * Starts the process represented by this builder, blocks until it exits, and returns the exit code.  Standard output and error are
-   * sent to the console.
-   */
-  def ! : Int
-  /**
-   * Starts the process represented by this builder, blocks until it exits, and returns the exit code.  Standard output and error are
-   * sent to the given ProcessLogger.
-   */
-  def !(log: ProcessLogger): Int
-  /**
-   * Starts the process represented by this builder, blocks until it exits, and returns the exit code.  Standard output and error are
-   * sent to the console.  The newly started process reads from standard input of the current process.
-   */
-  def !< : Int
-  /**
-   * Starts the process represented by this builder, blocks until it exits, and returns the exit code.  Standard output and error are
-   * sent to the given ProcessLogger.  The newly started process reads from standard input of the current process.
-   */
-  def !<(log: ProcessLogger): Int
-  /** Starts the process represented by this builder.  Standard output and error are sent to the console.*/
-  def run(): Process
-  /** Starts the process represented by this builder.  Standard output and error are sent to the given ProcessLogger.*/
-  def run(log: ProcessLogger): Process
-  /** Starts the process represented by this builder.  I/O is handled by the given ProcessIO instance.*/
-  def run(io: ProcessIO): Process
-  /**
-   * Starts the process represented by this builder.  Standard output and error are sent to the console.
-   * The newly started process reads from standard input of the current process if `connectInput` is true.
-   */
-  def run(connectInput: Boolean): Process
-  /**
-   * Starts the process represented by this builder, blocks until it exits, and returns the exit code.  Standard output and error are
-   * sent to the given ProcessLogger.
-   * The newly started process reads from standard input of the current process if `connectInput` is true.
-   */
-  def run(log: ProcessLogger, connectInput: Boolean): Process
-
-  def runBuffered(log: ProcessLogger, connectInput: Boolean): Process
-
-  /** Constructs a command that runs this command first and then `other` if this command succeeds.*/
-  def #&&(other: ProcessBuilder): ProcessBuilder
-  /** Constructs a command that runs this command first and then `other` if this command does not succeed.*/
-  def #||(other: ProcessBuilder): ProcessBuilder
-  /**
-   * Constructs a command that will run this command and pipes the output to `other`.
-   * `other` must be a simple command.
-   * The exit code will be that of `other` regardless of whether this command succeeds.
-   */
-  def #|(other: ProcessBuilder): ProcessBuilder
-  /** Constructs a command that will run this command and then `other`.  The exit code will be the exit code of `other`.*/
-  def ###(other: ProcessBuilder): ProcessBuilder
-
-  def canPipeTo: Boolean
-}
-/** Each method will be called in a separate thread.*/
-final class ProcessIO(val writeInput: OutputStream => Unit, val processOutput: InputStream => Unit, val processError: InputStream => Unit, val inheritInput: JProcessBuilder => Boolean) extends NotNull {
-  def withOutput(process: InputStream => Unit): ProcessIO = new ProcessIO(writeInput, process, processError, inheritInput)
-  def withError(process: InputStream => Unit): ProcessIO = new ProcessIO(writeInput, processOutput, process, inheritInput)
-  def withInput(write: OutputStream => Unit): ProcessIO = new ProcessIO(write, processOutput, processError, inheritInput)
-}
-trait ProcessLogger {
-  def info(s: => String): Unit
-  def error(s: => String): Unit
-  def buffer[T](f: => T): T
-}
diff --git a/launcher-package/integration-test/src/test/scala/ProcessImpl.scala b/launcher-package/integration-test/src/test/scala/ProcessImpl.scala
deleted file mode 100644
index b53998a39..000000000
--- a/launcher-package/integration-test/src/test/scala/ProcessImpl.scala
+++ /dev/null
@@ -1,433 +0,0 @@
-package sbt.internal
-
-import java.lang.{ Process => JProcess, ProcessBuilder => JProcessBuilder }
-import java.io.{ BufferedReader, Closeable, InputStream, InputStreamReader, IOException, OutputStream, PrintStream }
-import java.io.{ FilterInputStream, FilterOutputStream, PipedInputStream, PipedOutputStream }
-import java.io.{ File, FileInputStream, FileOutputStream }
-import java.net.URL
-
-/** Runs provided code in a new Thread and returns the Thread instance. */
-private object Spawn {
-  def apply(f: => Unit): Thread = apply(f, false)
-  def apply(f: => Unit, daemon: Boolean): Thread =
-    {
-      val thread = new Thread() { override def run() = { f } }
-      thread.setDaemon(daemon)
-      thread.start()
-      thread
-    }
-}
-private object Future {
-  def apply[T](f: => T): () => T =
-    {
-      val result = new SyncVar[Either[Throwable, T]]
-      def run(): Unit =
-        try { result.set(Right(f)) }
-        catch { case e: Exception => result.set(Left(e)) }
-      Spawn(run)
-      () =>
-        result.get match {
-          case Right(value)    => value
-          case Left(exception) => throw exception
-        }
-    }
-}
-
-object BasicIO {
-  def apply(buffer: StringBuffer, log: Option[ProcessLogger], withIn: Boolean) = new ProcessIO(input(withIn), processFully(buffer), getErr(log), inheritInput(withIn))
-  def apply(log: ProcessLogger, withIn: Boolean) = new ProcessIO(input(withIn), processInfoFully(log), processErrFully(log), inheritInput(withIn))
-
-  def getErr(log: Option[ProcessLogger]) = log match { case Some(lg) => processErrFully(lg); case None => toStdErr }
-
-  private def processErrFully(log: ProcessLogger) = processFully(s => log.error(s))
-  private def processInfoFully(log: ProcessLogger) = processFully(s => log.info(s))
-
-  def closeOut = (_: OutputStream).close()
-  final val BufferSize = 8192
-  final val Newline = System.getProperty("line.separator")
-
-  def close(c: java.io.Closeable) = try { c.close() } catch { case _: java.io.IOException => () }
-  def processFully(buffer: Appendable): InputStream => Unit = processFully(appendLine(buffer))
-  def processFully(processLine: String => Unit): InputStream => Unit =
-    in =>
-      {
-        val reader = new BufferedReader(new InputStreamReader(in))
-        processLinesFully(processLine)(reader.readLine)
-        reader.close()
-      }
-  def processLinesFully(processLine: String => Unit)(readLine: () => String): Unit = {
-    def readFully(): Unit = {
-      val line = readLine()
-      if (line != null) {
-        processLine(line)
-        readFully()
-      }
-    }
-    readFully()
-  }
-  def connectToIn(o: OutputStream): Unit = transferFully(Uncloseable protect System.in, o)
-  def input(connect: Boolean): OutputStream => Unit = if (connect) connectToIn else closeOut
-  def standard(connectInput: Boolean): ProcessIO = standard(input(connectInput), inheritInput(connectInput))
-  def standard(in: OutputStream => Unit, inheritIn: JProcessBuilder => Boolean): ProcessIO = new ProcessIO(in, toStdOut, toStdErr, inheritIn)
-
-  def toStdErr = (in: InputStream) => transferFully(in, System.err)
-  def toStdOut = (in: InputStream) => transferFully(in, System.out)
-
-  def transferFully(in: InputStream, out: OutputStream): Unit =
-    try { transferFullyImpl(in, out) }
-    catch { case _: InterruptedException => () }
-
-  private def appendLine(buffer: Appendable): String => Unit =
-    line =>
-      {
-        buffer.append(line)
-        buffer.append(Newline)
-      }
-
-  private def transferFullyImpl(in: InputStream, out: OutputStream): Unit = {
-    val continueCount = 1 //if(in.isInstanceOf[PipedInputStream]) 1 else 0
-    val buffer = new Array[Byte](BufferSize)
-    def read(): Unit = {
-      val byteCount = in.read(buffer)
-      if (byteCount >= continueCount) {
-        out.write(buffer, 0, byteCount)
-        out.flush()
-        read
-      }
-    }
-    read
-    in.close()
-  }
-
-  def inheritInput(connect: Boolean) = { (p: JProcessBuilder) => if (connect) InheritInput(p) else false }
-}
-private[sbt] object ExitCodes {
-  def ignoreFirst: (Int, Int) => Int = (a, b) => b
-  def firstIfNonzero: (Int, Int) => Int = (a, b) => if (a != 0) a else b
-}
-
-private[sbt] abstract class AbstractProcessBuilder extends ProcessBuilder with SinkPartialBuilder with SourcePartialBuilder {
-  def #&&(other: ProcessBuilder): ProcessBuilder = new AndProcessBuilder(this, other)
-  def #||(other: ProcessBuilder): ProcessBuilder = new OrProcessBuilder(this, other)
-  def #|(other: ProcessBuilder): ProcessBuilder =
-    {
-      require(other.canPipeTo, "Piping to multiple processes is not supported.")
-      new PipedProcessBuilder(this, other, false, exitCode = ExitCodes.ignoreFirst)
-    }
-  def ###(other: ProcessBuilder): ProcessBuilder = new SequenceProcessBuilder(this, other)
-
-  protected def toSource = this
-  protected def toSink = this
-
-  def run(): Process = run(false)
-  def run(connectInput: Boolean): Process = run(BasicIO.standard(connectInput))
-  def run(log: ProcessLogger): Process = run(log, false)
-  def run(log: ProcessLogger, connectInput: Boolean): Process = run(BasicIO(log, connectInput))
-
-  private def getString(log: Option[ProcessLogger], withIn: Boolean): String =
-    {
-      val buffer = new StringBuffer
-      val code = this ! BasicIO(buffer, log, withIn)
-      if (code == 0) buffer.toString else sys.error("Nonzero exit value: " + code)
-    }
-  def !! = getString(None, false)
-  def !!(log: ProcessLogger) = getString(Some(log), false)
-  def !!< = getString(None, true)
-  def !!<(log: ProcessLogger) = getString(Some(log), true)
-
-  def lines: Stream[String] = lines(false, true, None)
-  def lines(log: ProcessLogger): Stream[String] = lines(false, true, Some(log))
-  def lines_! : Stream[String] = lines(false, false, None)
-  def lines_!(log: ProcessLogger): Stream[String] = lines(false, false, Some(log))
-
-  private def lines(withInput: Boolean, nonZeroException: Boolean, log: Option[ProcessLogger]): Stream[String] =
-    {
-      val streamed = Streamed[String](nonZeroException)
-      val process = run(new ProcessIO(BasicIO.input(withInput), BasicIO.processFully(streamed.process), BasicIO.getErr(log), BasicIO.inheritInput(withInput)))
-      Spawn { streamed.done(process.exitValue()) }
-      streamed.stream()
-    }
-
-  def ! = run(false).exitValue()
-  def !< = run(true).exitValue()
-  def !(log: ProcessLogger) = runBuffered(log, false).exitValue()
-  def !<(log: ProcessLogger) = runBuffered(log, true).exitValue()
-  def runBuffered(log: ProcessLogger, connectInput: Boolean) =
-    log.buffer { run(log, connectInput) }
-  def !(io: ProcessIO) = run(io).exitValue()
-
-  def canPipeTo = false
-}
-
-private[sbt] class URLBuilder(url: URL) extends URLPartialBuilder with SourcePartialBuilder {
-  protected def toSource = new URLInput(url)
-}
-private[sbt] class FileBuilder(base: File) extends FilePartialBuilder with SinkPartialBuilder with SourcePartialBuilder {
-  protected def toSource = new FileInput(base)
-  protected def toSink = new FileOutput(base, false)
-  def #<<(f: File): ProcessBuilder = #<<(new FileInput(f))
-  def #<<(u: URL): ProcessBuilder = #<<(new URLInput(u))
-  def #<<(s: => InputStream): ProcessBuilder = #<<(new InputStreamBuilder(s))
-  def #<<(b: ProcessBuilder): ProcessBuilder = new PipedProcessBuilder(b, new FileOutput(base, true), false, ExitCodes.firstIfNonzero)
-}
-
-private abstract class BasicBuilder extends AbstractProcessBuilder {
-  protected def checkNotThis(a: ProcessBuilder) = require(a != this, "Compound process '" + a + "' cannot contain itself.")
-  final def run(io: ProcessIO): Process =
-    {
-      val p = createProcess(io)
-      p.start()
-      p
-    }
-  protected def createProcess(io: ProcessIO): BasicProcess
-}
-private abstract class BasicProcess extends Process {
-  def start(): Unit
-}
-
-private abstract class CompoundProcess extends BasicProcess {
-  def destroy(): Unit = destroyer()
-  def exitValue() = getExitValue().getOrElse(sys.error("No exit code: process destroyed."))
-
-  def start() = getExitValue
-
-  protected lazy val (getExitValue, destroyer) =
-    {
-      val code = new SyncVar[Option[Int]]()
-      code.set(None)
-      val thread = Spawn(code.set(runAndExitValue()))
-
-      (
-        Future { thread.join(); code.get },
-        () => thread.interrupt()
-      )
-    }
-
-  /** Start and block until the exit value is available and then return it in Some.  Return None if destroyed (use 'run')*/
-  protected def runAndExitValue(): Option[Int]
-
-  protected def runInterruptible[T](action: => T)(destroyImpl: => Unit): Option[T] =
-    {
-      try { Some(action) }
-      catch { case _: InterruptedException => destroyImpl; None }
-    }
-}
-
-private abstract class SequentialProcessBuilder(a: ProcessBuilder, b: ProcessBuilder, operatorString: String) extends BasicBuilder {
-  checkNotThis(a)
-  checkNotThis(b)
-  override def toString = " ( " + a + " " + operatorString + " " + b + " ) "
-}
-private class PipedProcessBuilder(first: ProcessBuilder, second: ProcessBuilder, toError: Boolean, exitCode: (Int, Int) => Int) extends SequentialProcessBuilder(first, second, if (toError) "#|!" else "#|") {
-  override def createProcess(io: ProcessIO) = new PipedProcesses(first, second, io, toError, exitCode)
-}
-private class AndProcessBuilder(first: ProcessBuilder, second: ProcessBuilder) extends SequentialProcessBuilder(first, second, "#&&") {
-  override def createProcess(io: ProcessIO) = new AndProcess(first, second, io)
-}
-private class OrProcessBuilder(first: ProcessBuilder, second: ProcessBuilder) extends SequentialProcessBuilder(first, second, "#||") {
-  override def createProcess(io: ProcessIO) = new OrProcess(first, second, io)
-}
-private class SequenceProcessBuilder(first: ProcessBuilder, second: ProcessBuilder) extends SequentialProcessBuilder(first, second, "###") {
-  override def createProcess(io: ProcessIO) = new ProcessSequence(first, second, io)
-}
-
-private class SequentialProcess(a: ProcessBuilder, b: ProcessBuilder, io: ProcessIO, evaluateSecondProcess: Int => Boolean) extends CompoundProcess {
-  protected override def runAndExitValue() =
-    {
-      val first = a.run(io)
-      runInterruptible(first.exitValue)(first.destroy()) flatMap
-        { codeA =>
-          if (evaluateSecondProcess(codeA)) {
-            val second = b.run(io)
-            runInterruptible(second.exitValue)(second.destroy())
-          } else
-            Some(codeA)
-        }
-    }
-}
-private class AndProcess(a: ProcessBuilder, b: ProcessBuilder, io: ProcessIO) extends SequentialProcess(a, b, io, _ == 0)
-private class OrProcess(a: ProcessBuilder, b: ProcessBuilder, io: ProcessIO) extends SequentialProcess(a, b, io, _ != 0)
-private class ProcessSequence(a: ProcessBuilder, b: ProcessBuilder, io: ProcessIO) extends SequentialProcess(a, b, io, ignore => true)
-
-private class PipedProcesses(a: ProcessBuilder, b: ProcessBuilder, defaultIO: ProcessIO, toError: Boolean, exitCode: (Int, Int) => Int) extends CompoundProcess {
-  protected override def runAndExitValue() =
-    {
-      val currentSource = new SyncVar[Option[InputStream]]
-      val pipeOut = new PipedOutputStream
-      val source = new PipeSource(currentSource, pipeOut, a.toString)
-      source.start()
-
-      val pipeIn = new PipedInputStream(pipeOut)
-      val currentSink = new SyncVar[Option[OutputStream]]
-      val sink = new PipeSink(pipeIn, currentSink, b.toString)
-      sink.start()
-
-      def handleOutOrError(fromOutput: InputStream) = currentSource.put(Some(fromOutput))
-
-      val firstIO =
-        if (toError)
-          defaultIO.withError(handleOutOrError)
-        else
-          defaultIO.withOutput(handleOutOrError)
-      val secondIO = defaultIO.withInput(toInput => currentSink.put(Some(toInput)))
-
-      val second = b.run(secondIO)
-      val first = a.run(firstIO)
-      try {
-        runInterruptible {
-          val firstResult = first.exitValue
-          currentSource.put(None)
-          currentSink.put(None)
-          val secondResult = second.exitValue
-          exitCode(firstResult, secondResult)
-        } {
-          first.destroy()
-          second.destroy()
-        }
-      } finally {
-        BasicIO.close(pipeIn)
-        BasicIO.close(pipeOut)
-      }
-    }
-}
-private class PipeSource(currentSource: SyncVar[Option[InputStream]], pipe: PipedOutputStream, label: => String) extends Thread {
-  final override def run(): Unit = {
-    currentSource.get match {
-      case Some(source) =>
-        try { BasicIO.transferFully(source, pipe) }
-        catch { case e: IOException => println("I/O error " + e.getMessage + " for process: " + label); e.printStackTrace() }
-        finally {
-          BasicIO.close(source)
-          currentSource.unset()
-        }
-        run()
-      case None =>
-        currentSource.unset()
-        BasicIO.close(pipe)
-    }
-  }
-}
-private class PipeSink(pipe: PipedInputStream, currentSink: SyncVar[Option[OutputStream]], label: => String) extends Thread {
-  final override def run(): Unit = {
-    currentSink.get match {
-      case Some(sink) =>
-        try { BasicIO.transferFully(pipe, sink) }
-        catch { case e: IOException => println("I/O error " + e.getMessage + " for process: " + label); e.printStackTrace() }
-        finally {
-          BasicIO.close(sink)
-          currentSink.unset()
-        }
-        run()
-      case None =>
-        currentSink.unset()
-    }
-  }
-}
-
-private[sbt] class DummyProcessBuilder(override val toString: String, exitValue: => Int) extends AbstractProcessBuilder {
-  override def run(io: ProcessIO): Process = new DummyProcess(exitValue)
-  override def canPipeTo = true
-}
-/**
- * A thin wrapper around a java.lang.Process.  `ioThreads` are the Threads created to do I/O.
- * The implementation of `exitValue` waits until these threads die before returning.
- */
-private class DummyProcess(action: => Int) extends Process {
-  private val exitCode = Future(action)
-  override def exitValue() = exitCode()
-  override def destroy(): Unit = ()
-}
-/** Represents a simple command without any redirection or combination. */
-private[sbt] class SimpleProcessBuilder(p: JProcessBuilder) extends AbstractProcessBuilder {
-  override def run(io: ProcessIO): Process =
-    {
-      import io._
-      val inherited = inheritInput(p)
-      val process = p.start()
-
-      // spawn threads that process the output and error streams, and also write input if not inherited.
-      if (!inherited)
-        Spawn(writeInput(process.getOutputStream))
-      val outThread = Spawn(processOutput(process.getInputStream))
-      val errorThread =
-        if (!p.redirectErrorStream)
-          Spawn(processError(process.getErrorStream)) :: Nil
-        else
-          Nil
-      new SimpleProcess(process, outThread :: errorThread)
-    }
-  override def toString = p.command.toString
-  override def canPipeTo = true
-}
-
-/**
- * A thin wrapper around a java.lang.Process. `outputThreads` are the Threads created to read from the
- * output and error streams of the process.
- * The implementation of `exitValue` wait for the process to finish and then waits until the threads reading output and error streams die before
- * returning. Note that the thread that reads the input stream cannot be interrupted, see https://github.com/sbt/sbt/issues/327 and
- * http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4514257
- */
-private class SimpleProcess(p: JProcess, outputThreads: List[Thread]) extends Process {
-  override def exitValue() =
-    {
-      try {
-        p.waitFor()
-      } catch {
-        case _: InterruptedException => p.destroy()
-      }
-      outputThreads.foreach(_.join()) // this ensures that all output is complete before returning (waitFor does not ensure this)
-      p.exitValue()
-    }
-  override def destroy() = p.destroy()
-}
-
-private[sbt] class FileOutput(file: File, append: Boolean) extends OutputStreamBuilder(new FileOutputStream(file, append), file.getAbsolutePath)
-private[sbt] class URLInput(url: URL) extends InputStreamBuilder(url.openStream, url.toString)
-private[sbt] class FileInput(file: File) extends InputStreamBuilder(new FileInputStream(file), file.getAbsolutePath)
-
-import Uncloseable.protect
-private[sbt] class OutputStreamBuilder(stream: => OutputStream, label: String) extends ThreadProcessBuilder(label, _.writeInput(protect(stream))) {
-  def this(stream: => OutputStream) = this(stream, "<output stream>")
-}
-private[sbt] class InputStreamBuilder(stream: => InputStream, label: String) extends ThreadProcessBuilder(label, _.processOutput(protect(stream))) {
-  def this(stream: => InputStream) = this(stream, "<input stream>")
-}
-
-private[sbt] abstract class ThreadProcessBuilder(override val toString: String, runImpl: ProcessIO => Unit) extends AbstractProcessBuilder {
-  override def run(io: ProcessIO): Process =
-    {
-      val success = new SyncVar[Boolean]
-      success.put(false)
-      new ThreadProcess(Spawn { runImpl(io); success.set(true) }, success)
-    }
-}
-private[sbt] final class ThreadProcess(thread: Thread, success: SyncVar[Boolean]) extends Process {
-  override def exitValue() =
-    {
-      thread.join()
-      if (success.get) 0 else 1
-    }
-  override def destroy(): Unit = thread.interrupt()
-}
-
-object Uncloseable {
-  def apply(in: InputStream): InputStream = new FilterInputStream(in) { override def close(): Unit = () }
-  def apply(out: OutputStream): OutputStream = new FilterOutputStream(out) { override def close(): Unit = () }
-  def protect(in: InputStream): InputStream = if (in eq System.in) Uncloseable(in) else in
-  def protect(out: OutputStream): OutputStream = if ((out eq System.out) || (out eq System.err)) Uncloseable(out) else out
-}
-private[sbt] object Streamed {
-  def apply[T](nonzeroException: Boolean): Streamed[T] =
-    {
-      val q = new java.util.concurrent.LinkedBlockingQueue[Either[Int, T]]
-      def next(): Stream[T] =
-        q.take match {
-          case Left(0)    => Stream.empty
-          case Left(code) => if (nonzeroException) sys.error("Nonzero exit code: " + code) else Stream.empty
-          case Right(s)   => Stream.cons(s, next)
-        }
-      new Streamed((s: T) => q.put(Right(s)), code => q.put(Left(code)), () => next())
-    }
-}
-
-private[sbt] final class Streamed[T](val process: T => Unit, val done: Int => Unit, val stream: () => Stream[T]) extends NotNull
\ No newline at end of file
diff --git a/launcher-package/integration-test/src/test/scala/RunnerMemoryScriptTest.scala b/launcher-package/integration-test/src/test/scala/RunnerMemoryScriptTest.scala
new file mode 100644
index 000000000..3978c4fb3
--- /dev/null
+++ b/launcher-package/integration-test/src/test/scala/RunnerMemoryScriptTest.scala
@@ -0,0 +1,77 @@
+package example.test
+
+/**
+ * RunnerMemoryScriptTest is used to test the sbt shell script, for both macOS/Linux and Windows.
+ */
+object RunnerMemoryScriptTest extends verify.BasicTestSuite with ShellScriptUtil:
+
+  testOutput("sbt -mem 503")("-mem", "503", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Xmx503m"))
+
+  testOutput("sbt with -mem 503, -Xmx in JAVA_OPTS", javaOpts = "-Xmx1024m")("-mem", "503", "-v"):
+    (out: List[String]) =>
+      assert(out.contains[String]("-Xmx503m"))
+      assert(!out.contains[String]("-Xmx1024m"))
+
+  testOutput("sbt with -mem 503, -Xmx in SBT_OPTS", sbtOpts = "-Xmx1024m")("-mem", "503", "-v"):
+    (out: List[String]) =>
+      assert(out.contains[String]("-Xmx503m"))
+      assert(!out.contains[String]("-Xmx1024m"))
+
+  testOutput("sbt with -mem 503, -Xss in JAVA_OPTS", javaOpts = "-Xss6m")("-mem", "503", "-v"):
+    (out: List[String]) =>
+      assert(out.contains[String]("-Xmx503m"))
+      assert(!out.contains[String]("-Xss6m"))
+
+  testOutput("sbt with -mem 503, -Xss in SBT_OPTS", sbtOpts = "-Xss6m")("-mem", "503", "-v"):
+    (out: List[String]) =>
+      assert(out.contains[String]("-Xmx503m"))
+      assert(!out.contains[String]("-Xss6m"))
+
+  testOutput(
+    "sbt with -Xms2048M -Xmx2048M -Xss6M in JAVA_OPTS",
+    javaOpts = "-Xms2048M -Xmx2048M -Xss6M"
+  )("-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Xms2048M"))
+    assert(out.contains[String]("-Xmx2048M"))
+    assert(out.contains[String]("-Xss6M"))
+
+  testOutput(
+    "sbt with -Xms2048M -Xmx2048M -Xss6M in SBT_OPTS",
+    sbtOpts = "-Xms2048M -Xmx2048M -Xss6M"
+  )("-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Xms2048M"))
+    assert(out.contains[String]("-Xmx2048M"))
+    assert(out.contains[String]("-Xss6M"))
+
+  testOutput(
+    "sbt use .sbtopts file for memory options",
+    sbtOptsFileContents = """-J-XX:MaxInlineLevel=20
+        |-J-Xmx222m
+        |-J-Xms111m
+        |-J-Xss12m""".stripMargin
+  )("compile", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-XX:MaxInlineLevel=20"))
+    assert(out.contains[String]("-Xmx222m"))
+    assert(out.contains[String]("-Xms111m"))
+    assert(out.contains[String]("-Xss12m"))
+
+  testOutput(
+    "sbt use JAVA_OPTS for memory options",
+    javaOpts = "-XX:MaxInlineLevel=20 -Xmx222m -Xms111m -Xss12m"
+  )("compile", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-XX:MaxInlineLevel=20"))
+    assert(out.contains[String]("-Xmx222m"))
+    assert(out.contains[String]("-Xms111m"))
+    assert(out.contains[String]("-Xss12m"))
+
+  testOutput(
+    "sbt use JAVA_TOOL_OPTIONS for memory options",
+    javaToolOptions = "-XX:MaxInlineLevel=20 -Xmx222m -Xms111m -Xss12m"
+  )("compile", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-XX:MaxInlineLevel=20"))
+    assert(out.contains[String]("-Xmx222m"))
+    assert(out.contains[String]("-Xms111m"))
+    assert(out.contains[String]("-Xss12m"))
+
+end RunnerMemoryScriptTest
diff --git a/launcher-package/integration-test/src/test/scala/RunnerScriptTest.scala b/launcher-package/integration-test/src/test/scala/RunnerScriptTest.scala
new file mode 100644
index 000000000..df02ee0ef
--- /dev/null
+++ b/launcher-package/integration-test/src/test/scala/RunnerScriptTest.scala
@@ -0,0 +1,125 @@
+package example.test
+
+/**
+ * RunnerScriptTest is used to test the sbt shell script, for both macOS/Linux and Windows.
+ */
+object RunnerScriptTest extends verify.BasicTestSuite with ShellScriptUtil:
+
+  testOutput("sbt -no-colors")("compile", "-no-colors", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.log.noformat=true"))
+
+  testOutput("sbt --no-colors")("compile", "--no-colors", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.log.noformat=true"))
+
+  testOutput("sbt --color=false")("compile", "--color=false", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.color=false"))
+
+  testOutput("sbt --no-colors in SBT_OPTS", sbtOpts = "--no-colors")("compile", "-v"):
+    (out: List[String]) =>
+      if (isWindows) cancel("Test not supported on windows")
+      assert(out.contains[String]("-Dsbt.log.noformat=true"))
+
+  testOutput("sbt --no-server")("compile", "--no-server", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.server.autostart=false"))
+
+  testOutput("sbt --debug-inc")("compile", "--debug-inc", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dxsbt.inc.debug=true"))
+
+  testOutput("sbt --supershell=never")("compile", "--supershell=never", "-v"):
+    (out: List[String]) => assert(out.contains[String]("-Dsbt.supershell=never"))
+
+  testOutput("sbt --timings")("compile", "--timings", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.task.timings=true"))
+
+  testOutput("sbt -D arguments")("-Dsbt.supershell=false", "compile", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.supershell=false"))
+
+  testOutput("sbt --sbt-version")("--sbt-version", "1.3.13", "-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.version=1.3.13"))
+
+  testOutput(
+    name = "sbt with -Dhttp.proxyHost=proxy -Dhttp.proxyPort=8080 in SBT_OPTS",
+    sbtOpts = "-Dhttp.proxyHost=proxy -Dhttp.proxyPort=8080",
+  )("-v"): (out: List[String]) =>
+    assert(out.contains[String]("-Dhttp.proxyHost=proxy"))
+    assert(out.contains[String]("-Dhttp.proxyPort=8080"))
+
+  testOutput(
+    name = "sbt with -XX:ParallelGCThreads=16 -XX:PermSize=128M in SBT_OPTS",
+    sbtOpts = "-XX:ParallelGCThreads=16 -XX:PermSize=128M",
+  )("-v"): (out: List[String]) =>
+    assert(out.contains[String]("-XX:ParallelGCThreads=16"))
+    assert(out.contains[String]("-XX:PermSize=128M"))
+
+  testOutput(
+    "sbt with -XX:+UseG1GC -XX:+PrintGC in JAVA_OPTS",
+    javaOpts = "-XX:+UseG1GC -XX:+PrintGC"
+  )("-v"): (out: List[String]) =>
+    assert(out.contains[String]("-XX:+UseG1GC"))
+    assert(out.contains[String]("-XX:+PrintGC"))
+    assert(!out.contains[String]("-XX:+UseG1GC=-XX:+PrintGC"))
+
+  testOutput(
+    "sbt with -XX:-UseG1GC -XX:-PrintGC in SBT_OPTS",
+    sbtOpts = "-XX:+UseG1GC -XX:+PrintGC"
+  )(
+    "-v"
+  ): (out: List[String]) =>
+    assert(out.contains[String]("-XX:+UseG1GC"))
+    assert(out.contains[String]("-XX:+PrintGC"))
+    assert(!out.contains[String]("-XX:+UseG1GC=-XX:+PrintGC"))
+
+  testOutput(
+    "sbt with -debug in SBT_OPTS appears in sbt commands",
+    javaOpts = "",
+    sbtOpts = "-debug"
+  )("compile", "-v"): (out: List[String]) =>
+    if (isWindows) cancel("Test not supported on windows")
+
+    // Debug argument must appear in the 'commands' section (after the sbt-launch.jar argument) to work
+    val sbtLaunchMatcher = """^.+sbt-launch.jar["]{0,1}$""".r
+    val locationOfSbtLaunchJarArg = out.zipWithIndex.collectFirst {
+      case (arg, index) if sbtLaunchMatcher.findFirstIn(arg).nonEmpty => index
+    }
+
+    assert(locationOfSbtLaunchJarArg.nonEmpty)
+
+    val argsAfterSbtLaunch = out.drop(locationOfSbtLaunchJarArg.get)
+    assert(argsAfterSbtLaunch.contains("-debug"))
+    ()
+
+  testOutput("sbt --jvm-debug <port>")("--jvm-debug", "12345", "-v"): (out: List[String]) =>
+    assert(
+      out.contains[String]("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=12345")
+    )
+
+  // Regression test for https://github.com/sbt/sbt/issues/8100
+  // Debug agent output in SBT_OPTS should not break the launcher on Windows
+  testOutput(
+    "sbt with debug agent in SBT_OPTS",
+    sbtOpts = "-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=12346"
+  )("-v"): (out: List[String]) =>
+    assert(
+      out.contains[String]("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=12346")
+    )
+
+  testOutput("sbt --no-share adds three system properties")("--no-share"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.global.base=project/.sbtboot"))
+    assert(out.contains[String]("-Dsbt.boot.directory=project/.boot"))
+    assert(out.contains[String]("-Dsbt.ivy.home=project/.ivy"))
+
+  testOutput("accept `--ivy` in `SBT_OPTS`", sbtOpts = "--ivy /ivy/dir")("-v"):
+    (out: List[String]) =>
+      if (isWindows) cancel("Test not supported on windows")
+      else assert(out.contains[String]("-Dsbt.ivy.home=/ivy/dir"))
+
+  testOutput("sbt --script-version should print sbtVersion")("--script-version"):
+    (out: List[String]) =>
+      val expectedVersion = "^" + ExtendedRunnerTest.versionRegEx + "$"
+      assert(out.mkString(System.lineSeparator()).trim.matches(expectedVersion))
+      ()
+
+  testOutput("--sbt-cache")("--sbt-cache", "./cachePath"): (out: List[String]) =>
+    assert(out.contains[String]("-Dsbt.global.localcache=./cachePath"))
+
+end RunnerScriptTest
diff --git a/launcher-package/integration-test/src/test/scala/ScriptTest.scala b/launcher-package/integration-test/src/test/scala/ScriptTest.scala
deleted file mode 100644
index a14f8a97c..000000000
--- a/launcher-package/integration-test/src/test/scala/ScriptTest.scala
+++ /dev/null
@@ -1,274 +0,0 @@
-package example.test
-
-import minitest._
-import sbt.io.IO
-
-import java.io.File
-import java.io.PrintWriter
-import java.nio.file.Files
-
-object SbtScriptTest extends SimpleTestSuite with PowerAssertions {
-  lazy val isWindows: Boolean =
-    sys.props("os.name").toLowerCase(java.util.Locale.ENGLISH).contains("windows")
-  lazy val sbtScript =
-    if (isWindows) new File("target/universal/stage/bin/sbt.bat")
-    else new File("target/universal/stage/bin/sbt")
-
-  private val javaBinDir = new File("integration-test", "bin").getAbsolutePath
-
-  private def retry[A1](f: () => A1, maxAttempt: Int = 10): A1 =
-    try {
-      f()
-    } catch {
-      case _ if maxAttempt <= 1 =>
-        Thread.sleep(100)
-        retry(f, maxAttempt - 1)
-    }
-
-  def makeTest(
-      name: String,
-      javaOpts: String = "",
-      sbtOpts: String = "",
-      sbtOptsFileContents: String = "",
-      javaToolOptions: String = ""
-  )(args: String*)(f: List[String] => Any) = {
-    test(name) {
-      val workingDirectory = Files.createTempDirectory("sbt-launcher-package-test").toFile
-      retry(() => IO.copyDirectory(new File("citest"), workingDirectory))
-
-      try {
-        val sbtOptsFile = new File(workingDirectory, ".sbtopts")
-        sbtOptsFile.createNewFile()
-        val writer = new PrintWriter(sbtOptsFile)
-        try {
-          writer.write(sbtOptsFileContents)
-        } finally {
-          writer.close()
-        }
-        val path = sys.env.getOrElse("PATH", sys.env("Path"))
-        val out = sbt.internal.Process(
-          Seq(sbtScript.getAbsolutePath) ++ args,
-          workingDirectory,
-          "JAVA_OPTS" -> javaOpts,
-          "SBT_OPTS" -> sbtOpts,
-          "JAVA_TOOL_OPTIONS" -> javaToolOptions,
-          if (isWindows)
-            "JAVACMD" -> new File(javaBinDir, "java").getAbsolutePath()
-          else
-            "PATH" -> (javaBinDir + File.pathSeparator + path)
-        ).!!.linesIterator.toList
-        f(out)
-        ()
-      } finally {
-        IO.delete(workingDirectory)
-      }
-    }
-  }
-
-  makeTest("sbt -no-colors")("compile", "-no-colors", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.log.noformat=true"))
-  }
-
-  makeTest("sbt --no-colors")("compile", "--no-colors", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.log.noformat=true"))
-  }
-
-  makeTest("sbt --color=false")("compile", "--color=false", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.color=false"))
-  }
-
-  makeTest("sbt --no-colors in SBT_OPTS", sbtOpts = "--no-colors")("compile", "-v") {
-    out: List[String] =>
-      if (isWindows) cancel("Test not supported on windows")
-      assert(out.contains[String]("-Dsbt.log.noformat=true"))
-  }
-
-  makeTest("sbt --no-server")("compile", "--no-server", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.server.autostart=false"))
-  }
-
-  makeTest("sbt --debug-inc")("compile", "--debug-inc", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dxsbt.inc.debug=true"))
-  }
-
-  makeTest("sbt --supershell=never")("compile", "--supershell=never", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.supershell=never"))
-  }
-
-  makeTest("sbt --timings")("compile", "--timings", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.task.timings=true"))
-  }
-
-  makeTest("sbt -D arguments")("-Dsbt.supershell=false", "compile", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.supershell=false"))
-  }
-
-  makeTest("sbt --sbt-version")("--sbt-version", "1.3.13", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.version=1.3.13"))
-  }
-
-  makeTest("sbt -mem 503")("-mem", "503", "-v") { out: List[String] =>
-    assert(out.contains[String]("-Xmx503m"))
-  }
-
-  makeTest("sbt with -mem 503, -Xmx in JAVA_OPTS", javaOpts = "-Xmx1024m")("-mem", "503", "-v") {
-    out: List[String] =>
-      assert(out.contains[String]("-Xmx503m"))
-      assert(!out.contains[String]("-Xmx1024m"))
-  }
-
-  makeTest("sbt with -mem 503, -Xmx in SBT_OPTS", sbtOpts = "-Xmx1024m")("-mem", "503", "-v") {
-    out: List[String] =>
-      assert(out.contains[String]("-Xmx503m"))
-      assert(!out.contains[String]("-Xmx1024m"))
-  }
-
-  makeTest("sbt with -mem 503, -Xss in JAVA_OPTS", javaOpts = "-Xss6m")("-mem", "503", "-v") {
-    out: List[String] =>
-      assert(out.contains[String]("-Xmx503m"))
-      assert(!out.contains[String]("-Xss6m"))
-  }
-
-  makeTest("sbt with -mem 503, -Xss in SBT_OPTS", sbtOpts = "-Xss6m")("-mem", "503", "-v") {
-    out: List[String] =>
-      assert(out.contains[String]("-Xmx503m"))
-      assert(!out.contains[String]("-Xss6m"))
-  }
-
-  makeTest(
-    "sbt with -Xms2048M -Xmx2048M -Xss6M in JAVA_OPTS",
-    javaOpts = "-Xms2048M -Xmx2048M -Xss6M"
-  )("-v") { out: List[String] =>
-    assert(out.contains[String]("-Xms2048M"))
-    assert(out.contains[String]("-Xmx2048M"))
-    assert(out.contains[String]("-Xss6M"))
-  }
-
-  makeTest(
-    "sbt with -Xms2048M -Xmx2048M -Xss6M in SBT_OPTS",
-    sbtOpts = "-Xms2048M -Xmx2048M -Xss6M"
-  )("-v") { out: List[String] =>
-    assert(out.contains[String]("-Xms2048M"))
-    assert(out.contains[String]("-Xmx2048M"))
-    assert(out.contains[String]("-Xss6M"))
-  }
-
-  makeTest(
-    name = "sbt with -Dhttp.proxyHost=proxy -Dhttp.proxyPort=8080 in SBT_OPTS",
-    sbtOpts = "-Dhttp.proxyHost=proxy -Dhttp.proxyPort=8080",
-  )("-v") { out: List[String] =>
-    assert(out.contains[String]("-Dhttp.proxyHost=proxy"))
-    assert(out.contains[String]("-Dhttp.proxyPort=8080"))
-  }
-
-  makeTest(
-    name = "sbt with -XX:ParallelGCThreads=16 -XX:PermSize=128M in SBT_OPTS",
-    sbtOpts = "-XX:ParallelGCThreads=16 -XX:PermSize=128M",
-  )("-v") { out: List[String] =>
-    assert(out.contains[String]("-XX:ParallelGCThreads=16"))
-    assert(out.contains[String]("-XX:PermSize=128M"))
-  }
-
-  makeTest(
-    "sbt with -XX:+UseG1GC -XX:+PrintGC in JAVA_OPTS",
-    javaOpts = "-XX:+UseG1GC -XX:+PrintGC"
-  )("-v") { out: List[String] =>
-    assert(out.contains[String]("-XX:+UseG1GC"))
-    assert(out.contains[String]("-XX:+PrintGC"))
-    assert(!out.contains[String]("-XX:+UseG1GC=-XX:+PrintGC"))
-  }
-
-  makeTest("sbt with -XX:-UseG1GC -XX:-PrintGC in SBT_OPTS", sbtOpts = "-XX:+UseG1GC -XX:+PrintGC")(
-    "-v"
-  ) { out: List[String] =>
-    assert(out.contains[String]("-XX:+UseG1GC"))
-    assert(out.contains[String]("-XX:+PrintGC"))
-    assert(!out.contains[String]("-XX:+UseG1GC=-XX:+PrintGC"))
-  }
-
-  makeTest("sbt with -debug in SBT_OPTS appears in sbt commands", javaOpts = "", sbtOpts = "-debug")("compile", "-v") {out: List[String] =>
-    if (isWindows) cancel("Test not supported on windows")
-
-    // Debug argument must appear in the 'commands' section (after the sbt-launch.jar argument) to work
-    val sbtLaunchMatcher = """^.+sbt-launch.jar["]{0,1}$""".r
-    val locationOfSbtLaunchJarArg = out.zipWithIndex.collectFirst {
-      case (arg, index) if sbtLaunchMatcher.findFirstIn(arg).nonEmpty => index
-    }
-
-    assert(locationOfSbtLaunchJarArg.nonEmpty)
-
-    val argsAfterSbtLaunch = out.drop(locationOfSbtLaunchJarArg.get)
-    assert(argsAfterSbtLaunch.contains("-debug"))
-    ()
-  }
-
-  makeTest("sbt --jvm-debug <port>")("--jvm-debug", "12345", "-v") { out: List[String] =>
-    assert(
-      out.contains[String]("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=12345")
-    )
-  }
-
-  // Regression test for https://github.com/sbt/sbt/issues/8100
-  // Debug agent output in SBT_OPTS should not break the launcher on Windows
-  makeTest(
-    "sbt with debug agent in SBT_OPTS",
-    sbtOpts = "-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=12346"
-  )("-v") { out: List[String] =>
-    assert(
-      out.contains[String]("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=12346")
-    )
-  }
-
-  makeTest("sbt --no-share adds three system properties")("--no-share") { out: List[String] =>
-    assert(out.contains[String]("-Dsbt.global.base=project/.sbtboot"))
-    assert(out.contains[String]("-Dsbt.boot.directory=project/.boot"))
-    assert(out.contains[String]("-Dsbt.ivy.home=project/.ivy"))
-  }
-
-  makeTest("accept `--ivy` in `SBT_OPTS`", sbtOpts = "--ivy /ivy/dir")("-v") { out: List[String] =>
-    if (isWindows) cancel("Test not supported on windows")
-    assert(out.contains[String]("-Dsbt.ivy.home=/ivy/dir"))
-  }
-
-  makeTest("sbt --script-version should print sbtVersion")("--script-version") { out: List[String] =>
-    val expectedVersion = "^" + SbtRunnerTest.versionRegEx + "$"
-    assert(out.mkString(System.lineSeparator()).trim.matches(expectedVersion))
-    ()
-  }
-
-  makeTest("--sbt-cache")("--sbt-cache", "./cachePath") { out: List[String] =>
-    assert(out.contains[String](s"-Dsbt.global.localcache=./cachePath"))
-  }
-
-  makeTest(
-    "sbt use .sbtopts file for memory options", sbtOptsFileContents =
-      """-J-XX:MaxInlineLevel=20
-        |-J-Xmx222m
-        |-J-Xms111m
-        |-J-Xss12m""".stripMargin
-
-  )("compile", "-v") { out: List[String] =>
-    assert(out.contains[String]("-XX:MaxInlineLevel=20"))
-    assert(out.contains[String]("-Xmx222m"))
-    assert(out.contains[String]("-Xms111m"))
-    assert(out.contains[String]("-Xss12m"))
-  }
-
-  makeTest(
-    "sbt use JAVA_OPTS for memory options", javaOpts = "-XX:MaxInlineLevel=20 -Xmx222m -Xms111m -Xss12m"
-  )("compile", "-v") { out: List[String] =>
-    assert(out.contains[String]("-XX:MaxInlineLevel=20"))
-    assert(out.contains[String]("-Xmx222m"))
-    assert(out.contains[String]("-Xms111m"))
-    assert(out.contains[String]("-Xss12m"))
-  }
-
-  makeTest(
-    "sbt use JAVA_TOOL_OPTIONS for memory options", javaToolOptions = "-XX:MaxInlineLevel=20 -Xmx222m -Xms111m -Xss12m"
-  )("compile", "-v") { out: List[String] =>
-    assert(out.contains[String]("-XX:MaxInlineLevel=20"))
-    assert(out.contains[String]("-Xmx222m"))
-    assert(out.contains[String]("-Xms111m"))
-    assert(out.contains[String]("-Xss12m"))
-  }
-}
diff --git a/launcher-package/integration-test/src/test/scala/ShellScriptUtil.scala b/launcher-package/integration-test/src/test/scala/ShellScriptUtil.scala
new file mode 100644
index 000000000..87dcc8830
--- /dev/null
+++ b/launcher-package/integration-test/src/test/scala/ShellScriptUtil.scala
@@ -0,0 +1,71 @@
+package example.test
+
+import java.io.File
+import java.io.PrintWriter
+import java.nio.file.Files
+import sbt.io.IO
+import verify.BasicTestSuite
+
+trait ShellScriptUtil extends BasicTestSuite {
+  val isWindows: Boolean =
+    sys.props("os.name").toLowerCase(java.util.Locale.ENGLISH).contains("windows")
+
+  private val javaBinDir = new File("launcher-package/integration-test/bin").getAbsolutePath
+
+  private def retry[A1](f: () => A1, maxAttempt: Int = 10): A1 =
+    try {
+      f()
+    } catch {
+      case _ if maxAttempt <= 1 =>
+        Thread.sleep(100)
+        retry(f, maxAttempt - 1)
+    }
+
+  val sbtScript =
+    if (isWindows) new File("launcher-package/target/universal/stage/bin/sbt.bat")
+    else new File("launcher-package/target/universal/stage/bin/sbt")
+
+  /**
+   * testOutput is a helper function to create a test for shell script.
+   */
+  inline def testOutput(
+      name: String,
+      javaOpts: String = "",
+      sbtOpts: String = "",
+      sbtOptsFileContents: String = "",
+      javaToolOptions: String = ""
+  )(args: String*)(f: List[String] => Any) =
+    test(name) {
+      val workingDirectory = Files.createTempDirectory("sbt-launcher-package-test").toFile
+      retry(() => IO.copyDirectory(new File("launcher-package/citest"), workingDirectory))
+
+      try
+        val sbtOptsFile = new File(workingDirectory, ".sbtopts")
+        sbtOptsFile.createNewFile()
+        val writer = new PrintWriter(sbtOptsFile)
+        try {
+          writer.write(sbtOptsFileContents)
+        } finally {
+          writer.close()
+        }
+        val path = sys.env.getOrElse("PATH", sys.env("Path"))
+        val out = scala.sys.process
+          .Process(
+            Seq(sbtScript.getAbsolutePath) ++ args,
+            workingDirectory,
+            "JAVA_OPTS" -> javaOpts,
+            "SBT_OPTS" -> sbtOpts,
+            "JAVA_TOOL_OPTIONS" -> javaToolOptions,
+            if (isWindows)
+              "JAVACMD" -> new File(javaBinDir, "java").getAbsolutePath()
+            else
+              "PATH" -> (javaBinDir + File.pathSeparator + path)
+          )
+          .!!
+          .linesIterator
+          .toList
+        f(out)
+        ()
+      finally IO.delete(workingDirectory)
+    }
+}
diff --git a/launcher-package/integration-test/src/test/scala/SyncVar.scala b/launcher-package/integration-test/src/test/scala/SyncVar.scala
deleted file mode 100644
index e5c7294c5..000000000
--- a/launcher-package/integration-test/src/test/scala/SyncVar.scala
+++ /dev/null
@@ -1,38 +0,0 @@
-package sbt.internal
-
-// minimal copy of scala.concurrent.SyncVar since that version deprecated put and unset
-private[sbt] final class SyncVar[A] {
-  private var isDefined: Boolean = false
-  private var value: Option[A] = None
-
-  /** Waits until a value is set and then gets it.  Does not clear the value */
-  def get: A = synchronized {
-    while (!isDefined) wait()
-    value.get
-  }
-
-  /** Waits until a value is set, gets it, and finally clears the value. */
-  def take(): A = synchronized {
-    try get finally unset()
-  }
-
-  /** Sets the value, whether or not it is currently defined. */
-  def set(x: A): Unit = synchronized {
-    isDefined = true
-    value = Some(x)
-    notifyAll()
-  }
-
-  /** Sets the value, first waiting until it is undefined if it is currently defined. */
-  def put(x: A): Unit = synchronized {
-    while (isDefined) wait()
-    set(x)
-  }
-
-  /** Clears the value, whether or not it is current defined. */
-  def unset(): Unit = synchronized {
-    isDefined = false
-    value = None
-    notifyAll()
-  }
-}
diff --git a/launcher-package/project/build.properties b/launcher-package/project/build.properties
deleted file mode 100644
index 73df629ac..000000000
--- a/launcher-package/project/build.properties
+++ /dev/null
@@ -1 +0,0 @@
-sbt.version=1.10.7
diff --git a/launcher-package/project/plugins.sbt b/launcher-package/project/plugins.sbt
deleted file mode 100644
index 10a9e1796..000000000
--- a/launcher-package/project/plugins.sbt
+++ /dev/null
@@ -1,2 +0,0 @@
-addSbtPlugin("com.github.sbt" % "sbt-native-packager" % "1.10.4")
-addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.3.1")
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 0d01ae0df..a2c970b44 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -5,13 +5,14 @@ object Dependencies {
   // WARNING: Please Scala update versions in PluginCross.scala too
   val scala213 = "2.13.16"
   val scala3 = "3.7.4"
+  val scala212 = "2.12.21"
   val checkPluginCross = settingKey[Unit]("Make sure scalaVersion match up")
   val baseScalaVersion = scala3
   def nightlyVersion: Option[String] =
     sys.env.get("BUILD_VERSION") orElse sys.props.get("sbt.build.version")
 
   // sbt modules
-  private val ioVersion = nightlyVersion.getOrElse("1.10.5")
+  val ioVersion = nightlyVersion.getOrElse("1.10.5")
   val zincVersion = nightlyVersion.getOrElse("2.0.0-M11")
 
   private val sbtIO = "org.scala-sbt" %% "io" % ioVersion
diff --git a/launcher-package/project/PackageSignerPlugin.scala b/project/PackageSignerPlugin.scala
similarity index 72%
rename from launcher-package/project/PackageSignerPlugin.scala
rename to project/PackageSignerPlugin.scala
index c819dff6c..587b3e091 100644
--- a/launcher-package/project/PackageSignerPlugin.scala
+++ b/project/PackageSignerPlugin.scala
@@ -1,5 +1,5 @@
-import sbt._
-import Keys._
+import sbt.*
+import Keys.*
 import sbt.internal.librarymanagement.IvyActions
 import com.jsuereth.sbtpgp.SbtPgp
 import com.typesafe.sbt.packager.universal.{ UniversalPlugin, UniversalDeployPlugin }
@@ -11,20 +11,20 @@ object PackageSignerPlugin extends sbt.AutoPlugin {
   override def trigger = allRequirements
   override def requires = SbtPgp && UniversalDeployPlugin && DebianDeployPlugin && RpmDeployPlugin
 
-  import com.jsuereth.sbtpgp.PgpKeys._
-  import UniversalPlugin.autoImport._
-  import DebianPlugin.autoImport._
-  import RpmPlugin.autoImport._
+  import com.jsuereth.sbtpgp.PgpKeys.*
+  import UniversalPlugin.autoImport.*
+  import DebianPlugin.autoImport.*
+  import RpmPlugin.autoImport.*
 
-  override def projectSettings: Seq[Setting[_]] =
+  override def projectSettings: Seq[Setting[?]] =
     inConfig(Universal)(packageSignerSettings) ++
-    inConfig(Debian)(packageSignerSettings) ++
-    inConfig(Rpm)(packageSignerSettings)
+      inConfig(Debian)(packageSignerSettings) ++
+      inConfig(Rpm)(packageSignerSettings)
 
   def subExtension(art: Artifact, ext: String): Artifact =
     art.withExtension(ext)
 
-  def packageSignerSettings: Seq[Setting[_]] = Seq(
+  def packageSignerSettings: Seq[Setting[?]] = Seq(
     signedArtifacts := {
       val artifacts = packagedArtifacts.value
       val r = pgpSigner.value
@@ -32,33 +32,38 @@ object PackageSignerPlugin extends sbt.AutoPlugin {
       val s = streams.value
       if (!skipZ) {
         artifacts flatMap { case (art, f) =>
-          Seq(art -> f,
-              subExtension(art, art.extension + gpgExtension) ->
-              r.sign(f, file(f.getAbsolutePath + gpgExtension), s))
+          Seq(
+            art -> f,
+            subExtension(art, art.extension + gpgExtension) ->
+              r.sign(f, file(f.getAbsolutePath + gpgExtension), s)
+          )
         }
-      }
-      else artifacts
+      } else artifacts
     },
     publishSignedConfiguration := Classpaths.publishConfig(
       publishMavenStyle = publishMavenStyle.value,
-      deliverIvyPattern = (Compile / packageBin / artifactPath).value.getParent + "/[artifact]-[revision](-[classifier]).[ext]",
+      deliverIvyPattern =
+        (Compile / packageBin / artifactPath).value.getParent + "/[artifact]-[revision](-[classifier]).[ext]",
       status = if (isSnapshot.value) "integration" else "release",
       configurations = Vector.empty,
       artifacts = signedArtifacts.value.toVector,
       checksums = (publish / checksums).value.toVector,
       resolverName = Classpaths.getPublishTo(publishTo.value).name,
       logging = ivyLoggingLevel.value,
-      overwrite = isSnapshot.value),
+      overwrite = isSnapshot.value
+    ),
     publishLocalSignedConfiguration := Classpaths.publishConfig(
       publishMavenStyle = publishMavenStyle.value,
-      deliverIvyPattern = (Compile / packageBin / artifactPath).value.getParent + "/[artifact]-[revision](-[classifier]).[ext]",
+      deliverIvyPattern =
+        (Compile / packageBin / artifactPath).value.getParent + "/[artifact]-[revision](-[classifier]).[ext]",
       status = if (isSnapshot.value) "integration" else "release",
       configurations = Vector.empty,
       artifacts = signedArtifacts.value.toVector,
       checksums = (publish / checksums).value.toVector,
       resolverName = "local",
       logging = ivyLoggingLevel.value,
-      overwrite = isSnapshot.value),
+      overwrite = isSnapshot.value
+    ),
     publishSigned := Def.taskDyn {
       val config = publishSignedConfiguration.value
       val s = streams.value
@@ -76,4 +81,3 @@ object PackageSignerPlugin extends sbt.AutoPlugin {
   )
 
 }
-
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 337fb4bbe..010a62389 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -11,5 +11,6 @@ addSbtPlugin("com.swoval" % "sbt-java-format" % "0.3.1")
 addSbtPlugin("org.scalameta" % "sbt-native-image" % "0.3.4")
 addDependencyTreePlugin
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.14.3")
+addSbtPlugin("com.github.sbt" % "sbt-native-packager" % "1.10.4")
 
 // libraryDependencies += "org.scala-sbt" %% "scripted-plugin" % sbtVersion.value