From 51aa789346dd515d589c12ec00fcc0b1f1821484 Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Sun, 28 Sep 2025 04:06:37 -0400
Subject: [PATCH 01/17] Suppress JDK 25 warnings

---
 .github/workflows/client-test.yml          |  6 ++++--
 launcher-package/src/universal/bin/sbt.bat | 16 +++++++++++++++
 sbt                                        | 23 ++++++++++++++++++----
 3 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/client-test.yml b/.github/workflows/client-test.yml
index 9526d612a..8959c7861 100644
--- a/.github/workflows/client-test.yml
+++ b/.github/workflows/client-test.yml
@@ -33,7 +33,9 @@ jobs:
       uses: actions/setup-java@v5
       with:
         distribution: "zulu"
-        java-version: "8"
+        java-version: |
+          25
+          8
         cache: sbt
     - uses: sbt/setup-sbt@v1
       with:
@@ -60,7 +62,6 @@ jobs:
         sbt -Dsbt.build.version=$TEST_SBT_VER rpm:packageBin debian:packageBin
         sbt -Dsbt.build.version=$TEST_SBT_VER integrationTest/test
         cd citest && ./test.sh
-        $HOME/bin/jabba install $JDK11 && exec $HOME/bin/jabba which --home $JDK11
         java -Xmx32m -version
         ./test.sh
     - name: Client test (macOS)
@@ -91,4 +92,5 @@ jobs:
         sbt -Dsbt.build.version=$TEST_SBT_VER integrationTest/test
         cd citest
         ./test.bat
+        java -Xmx32m -version
         test3/test3.bat
diff --git a/launcher-package/src/universal/bin/sbt.bat b/launcher-package/src/universal/bin/sbt.bat
index 781b8b9ba..a8414490b 100755
--- a/launcher-package/src/universal/bin/sbt.bat
+++ b/launcher-package/src/universal/bin/sbt.bat
@@ -39,6 +39,7 @@ set sbt_args_color=
 set sbt_args_no_colors=
 set sbt_args_no_global=
 set sbt_args_no_share=
+set sbt_args_no_hide_jdk_warnings=
 set sbt_args_sbt_jar=
 set sbt_args_ivy=
 set sbt_args_supershell=
@@ -231,6 +232,14 @@ if defined _no_server_arg (
   goto args_loop
 )
 
+if "%~0" == "--no-hide-jdk-warnings" set _no_hide_jdk_warnings=true
+
+if defined _no_hide_jdk_warnings (
+  set _no_hide_jdk_warnings=
+  set sbt_args_no_hide_jdk_warnings=1
+  goto args_loop
+)
+
 if "%~0" == "-no-global" set _no_global_arg=true
 if "%~0" == "--no-global" set _no_global_arg=true
 
@@ -677,6 +686,13 @@ if defined sbt_args_no_server (
   set _SBT_OPTS=-Dsbt.io.virtual=false -Dsbt.server.autostart=false !_SBT_OPTS!
 )
 
+if not defined sbt_args_no_hide_jdk_warnings (
+  if /I !JAVA_VERSION! EQU 25 (
+    call :addJava --sun-misc-unsafe-memory-access=allow
+    call :addJava --enable-native-access=ALL-UNNAMED
+  )
+)
+
 rem TODO: _SBT_OPTS needs to be processed as args and diffed against SBT_ARGS
 
 if !sbt_args_print_sbt_version! equ 1 (
diff --git a/sbt b/sbt
index ea6860fe6..7f03aa622 100755
--- a/sbt
+++ b/sbt
@@ -28,6 +28,7 @@ declare sbtn_command="$SBTN_CMD"
 declare sbtn_version="1.11.6"
 declare use_colors=1
 declare is_this_dir_sbt=""
+declare hide_jdk_warnings=1
 
 ###  ------------------------------- ###
 ###  Helper methods for BASH scripts ###
@@ -85,7 +86,7 @@ CYGWIN_FLAG=$(if is_cygwin; then echo true; else echo false; fi)
 # windows style paths.
 cygwinpath() {
   local file="$1"
-  if [[ "$CYGWIN_FLAG" == "true" ]]; then #"
+  if [[ "$CYGWIN_FLAG" == "true" ]]; then
     echo $(cygpath -w $file)
   else
     echo $file
@@ -114,7 +115,7 @@ echoerr_error () {
     echoerr -e "[${RED}error${NC}] $@"
   else
     echoerr "[error] $@"
-  fi
+  fi #"
 }
 vlog () {
   [[ $sbt_verbose || $sbt_debug ]] && echoerr "$@"
@@ -347,6 +348,18 @@ addSbtScriptProperty () {
   fi
 }
 
+addJdkWorkaround () {
+  local is_25="$(expr $java_version "=" 25)"
+  if [[ "$hide_jdk_warnings" == "0" ]]; then
+    :
+  else
+    if [[ "$is_25" == "1" ]]; then
+      addJava "--sun-misc-unsafe-memory-access=allow"
+      addJava "--enable-native-access=ALL-UNNAMED"
+    fi
+  fi
+}
+
 require_arg () {
   local type="$1"
   local opt="$2"
@@ -532,7 +545,7 @@ run() {
   copyRt
 
   # If we're in cygwin, we should use the windows config, and terminal hacks
-  if [[ "$CYGWIN_FLAG" == "true" ]]; then #"
+  if [[ "$CYGWIN_FLAG" == "true" ]]; then
     stty -icanon min 1 -echo > /dev/null 2>&1
     addJava "-Djline.terminal=jline.UnixTerminal"
     addJava "-Dsbt.cygwin=true"
@@ -572,7 +585,7 @@ run() {
   exit_code=$?
 
   # Clean up the terminal from cygwin hacks.
-  if [[ "$CYGWIN_FLAG" == "true" ]]; then #"
+  if [[ "$CYGWIN_FLAG" == "true" ]]; then
     stty icanon echo > /dev/null 2>&1
   fi
   exit $exit_code
@@ -705,6 +718,7 @@ process_args () {
            -client|--client) use_sbtn=1 && shift ;;
                    --server) use_sbtn=0 && shift ;;
                --jvm-client) use_sbtn=0 && use_jvm_client=1 && addSbt "--client" && shift ;;
+     --no-hide-jdk-warnings) hide_jdk_warnings=0 && shift ;;
 
                  -mem|--mem) require_arg integer "$1" "$2" && addMemory "$2" && shift 2 ;;
      -jvm-debug|--jvm-debug) require_arg port "$1" "$2" && addDebugger $2 && shift 2 ;;
@@ -867,6 +881,7 @@ else
   vlog "[process_args] java_version = '$java_version'"
   addDefaultMemory
   addSbtScriptProperty
+  addJdkWorkaround
   set -- "${residual_args[@]}"
   argumentCount=$#
   run

From bd460ae5363b5fe6545576184633ff88cf9cc2f0 Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Sun, 28 Sep 2025 04:27:17 -0400
Subject: [PATCH 02/17] Test using JDK 25

---
 .github/workflows/client-test.yml          |  7 ++++---
 launcher-package/citest/test3/.jvmopts     |  2 +-
 launcher-package/citest/test3/build.sbt    |  6 +++---
 launcher-package/citest/test3/test3.bat    | 10 ++++++----
 launcher-package/src/universal/bin/sbt.bat |  3 +--
 5 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/.github/workflows/client-test.yml b/.github/workflows/client-test.yml
index 8959c7861..df0ef6ab4 100644
--- a/.github/workflows/client-test.yml
+++ b/.github/workflows/client-test.yml
@@ -57,11 +57,13 @@ jobs:
         ./client/target/bin/sbtn --sbt-script=$(pwd)/sbt about
         ./client/target/bin/sbtn --sbt-script=$(pwd)/sbt shutdown
         # test launcher script
-        echo build using JDK 8 test using JDK 8 and JDK 11
+        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
+        JAVA_HOME="$JAVA_HOME_25_X64"
+        PATH="$JAVA_HOME_25_X64/bin:$PATH"
         java -Xmx32m -version
         ./test.sh
     - name: Client test (macOS)
@@ -86,11 +88,10 @@ jobs:
         ./client/target/bin/sbtn --sbt-script=$(pwd)/launcher-package/src/universal/bin/sbt.bat about
         ./client/target/bin/sbtn --sbt-script=$(pwd)/launcher-package/src/universal/bin/sbt.bat shutdown
         # test launcher script
-        echo build using JDK 8, test using JDK 8, on Windows
+        echo build using JDK 8 test using JDK 8 and JDK 25
         cd launcher-package
         bin/coursier.bat resolve
         sbt -Dsbt.build.version=$TEST_SBT_VER integrationTest/test
         cd citest
         ./test.bat
-        java -Xmx32m -version
         test3/test3.bat
diff --git a/launcher-package/citest/test3/.jvmopts b/launcher-package/citest/test3/.jvmopts
index ecacefc9a..a18306841 100644
--- a/launcher-package/citest/test3/.jvmopts
+++ b/launcher-package/citest/test3/.jvmopts
@@ -1,3 +1,3 @@
--XX:+CMSClassUnloadingEnabled
+#-XX:+CMSClassUnloadingEnabled
 #-XX:ReservedCodeCacheSize=192m
 #-Duser.timezone=GMT
\ No newline at end of file
diff --git a/launcher-package/citest/test3/build.sbt b/launcher-package/citest/test3/build.sbt
index 6cba9926c..dbe7fe7f9 100755
--- a/launcher-package/citest/test3/build.sbt
+++ b/launcher-package/citest/test3/build.sbt
@@ -27,19 +27,19 @@ lazy val root = (project in file("."))
       assert(ys.size == 1, s"ys has more than one item: $ys")
       assert(ys(0) startsWith "Java HotSpot(TM) 64-Bit Server VM warning")
     },
-    checkNumericVersion = {
+    checkNumericVersion := {
       val xs = IO.readLines(file("numericVersion.txt")).toVector
       val expectedVersion = "^"+versionRegEx+"$"
 
       assert(xs(0).matches(expectedVersion))
     },
-    checkScriptVersion = {
+    checkScriptVersion := {
       val xs = IO.readLines(file("scriptVersion.txt")).toVector
       val expectedVersion = "^"+versionRegEx+"$"
 
       assert(xs(0).matches(expectedVersion))
     },
-    checkVersion = {
+    checkVersion := {
       val out = IO.readLines(file("version.txt")).toVector.mkString("\n")
 
       val expectedVersion =
diff --git a/launcher-package/citest/test3/test3.bat b/launcher-package/citest/test3/test3.bat
index 38b1bde4f..52f489a0f 100644
--- a/launcher-package/citest/test3/test3.bat
+++ b/launcher-package/citest/test3/test3.bat
@@ -2,16 +2,18 @@
 
 SETLOCAL
 
-SET JAVA_HOME=C:\jdk11
-SET PATH=C:\jdk11\bin;%PATH%
+SET JAVA_HOME=%JAVA_HOME_25_X64%
+SET PATH=%JAVA_HOME_25_X64%\bin;%PATH%
 SET SBT_OPTS=-Xmx4g -Dfile.encoding=UTF8
 
 SET BASE_DIR=%CD%
 SET SCRIPT_DIR=%~dp0
 
 CD %SCRIPT_DIR%
-"%BASE_DIR%freshly-baked\sbt\bin\sbt" about 1> output.txt 2> err.txt
-"%BASE_DIR%freshly-baked\sbt\bin\sbt" check
+"%BASE_DIR%\freshly-baked\sbt\bin\sbt" about 1> output.txt 2> err.txt
+"%BASE_DIR%\freshly-baked\sbt\bin\sbt" check
 CD %BASE_DIR%
 
 ENDLOCAL
+
+IF %errorlevel% NEQ 0 EXIT /b %errorlevel%
diff --git a/launcher-package/src/universal/bin/sbt.bat b/launcher-package/src/universal/bin/sbt.bat
index a8414490b..3c3468e2f 100755
--- a/launcher-package/src/universal/bin/sbt.bat
+++ b/launcher-package/src/universal/bin/sbt.bat
@@ -688,8 +688,7 @@ if defined sbt_args_no_server (
 
 if not defined sbt_args_no_hide_jdk_warnings (
   if /I !JAVA_VERSION! EQU 25 (
-    call :addJava --sun-misc-unsafe-memory-access=allow
-    call :addJava --enable-native-access=ALL-UNNAMED
+    set _SBT_OPTS=--sun-misc-unsafe-memory-access=allow --enable-native-access=ALL-UNNAMED !_SBT_OPTS!
   )
 )
 

From 246e060e537bd69830d0a883dcba179529a98119 Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Mon, 29 Sep 2025 07:37:05 +0900
Subject: [PATCH 03/17] update sbt-giter8-resolver version

---
 main/src/main/scala/sbt/plugins/Giter8TemplatePlugin.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/src/main/scala/sbt/plugins/Giter8TemplatePlugin.scala b/main/src/main/scala/sbt/plugins/Giter8TemplatePlugin.scala
index 4aedac6aa..d976909c7 100644
--- a/main/src/main/scala/sbt/plugins/Giter8TemplatePlugin.scala
+++ b/main/src/main/scala/sbt/plugins/Giter8TemplatePlugin.scala
@@ -27,7 +27,7 @@ object Giter8TemplatePlugin extends AutoPlugin {
           ModuleID(
             "org.scala-sbt.sbt-giter8-resolver",
             "sbt-giter8-resolver",
-            "0.17.0"
+            "0.18.0"
           ) cross CrossVersion.binary,
           "sbtgiter8resolver.Giter8TemplateResolver"
         )

From ded814f572c473f939d8719545d5d7bf011a9b5d Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Fri, 3 Oct 2025 09:21:52 +0900
Subject: [PATCH 04/17] update dependencies

---
 project/Dependencies.scala | 10 +++++-----
 project/build.properties   |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 8127eb1b8..17e157653 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -91,9 +91,9 @@ object Dependencies {
   val jline3Native = "org.jline" % "jline-native" % jline3Version
   val jline3Reader = "org.jline" % "jline-reader" % jline3Version
   val jline3Builtins = "org.jline" % "jline-builtins" % jline3Version
-  val scalatest = "org.scalatest" %% "scalatest" % "3.2.10"
-  val scalacheck = "org.scalacheck" %% "scalacheck" % "1.15.4"
-  val junit = "junit" % "junit" % "4.13.1"
+  val scalatest = "org.scalatest" %% "scalatest" % "3.2.19"
+  val scalacheck = "org.scalacheck" %% "scalacheck" % "1.19.0"
+  val junit = "junit" % "junit" % "4.13.2"
   val scalaVerify = "com.eed3si9n.verify" %% "verify" % "1.0.0"
   val templateResolverApi = "org.scala-sbt" % "template-resolver" % "0.1"
 
@@ -129,8 +129,8 @@ object Dependencies {
 
   val caffeine = "com.github.ben-manes.caffeine" % "caffeine" % "2.8.5"
 
-  val hedgehog = "qa.hedgehog" %% "hedgehog-sbt" % "0.7.0"
+  val hedgehog = "qa.hedgehog" %% "hedgehog-sbt" % "0.13.0"
   val disruptor = "com.lmax" % "disruptor" % "3.4.2"
-  val kindProjector = ("org.typelevel" % "kind-projector" % "0.13.3").cross(CrossVersion.full)
+  val kindProjector = ("org.typelevel" % "kind-projector" % "0.13.4").cross(CrossVersion.full)
   val gigahorseOkHttp = "com.eed3si9n" %% "gigahorse-apache-http" % "0.9.3"
 }
diff --git a/project/build.properties b/project/build.properties
index 489e0a72d..5e6884d37 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=1.11.4
+sbt.version=1.11.6

From 3b662f39688b54e6c43a6fc5f821a7749c806902 Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Fri, 3 Oct 2025 09:39:10 +0900
Subject: [PATCH 05/17] fix fallback-dependencies-inter-project test

---
 .../fallback-dependencies-inter-project/build.sbt               | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sbt-app/src/sbt-test/dependency-management/fallback-dependencies-inter-project/build.sbt b/sbt-app/src/sbt-test/dependency-management/fallback-dependencies-inter-project/build.sbt
index 98731216b..280188f55 100644
--- a/sbt-app/src/sbt-test/dependency-management/fallback-dependencies-inter-project/build.sbt
+++ b/sbt-app/src/sbt-test/dependency-management/fallback-dependencies-inter-project/build.sbt
@@ -2,7 +2,7 @@ ThisBuild / scalaVersion := "2.11.12"
 
 lazy val a = project
   .settings(
-    libraryDependencies += "com.chuusai" %% "shapeless" % "2.3.234" from "https://oss.sonatype.org/content/repositories/releases/com/chuusai/shapeless_2.11/2.3.1/shapeless_2.11-2.3.1.jar"
+    libraryDependencies += "com.chuusai" %% "shapeless" % "2.3.234" from "https://repo1.maven.org/maven2/com/chuusai/shapeless_2.11/2.3.1/shapeless_2.11-2.3.1.jar"
   )
 
 lazy val b = project

From 2a7e70ab6a7af9a8047eb184d28ada068e9f86c4 Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Fri, 3 Oct 2025 14:49:28 +0900
Subject: [PATCH 06/17] fix run/daemon-exit test

---
 sbt-app/src/sbt-test/run/daemon-exit/build.sbt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 sbt-app/src/sbt-test/run/daemon-exit/build.sbt

diff --git a/sbt-app/src/sbt-test/run/daemon-exit/build.sbt b/sbt-app/src/sbt-test/run/daemon-exit/build.sbt
new file mode 100644
index 000000000..6dbf94cfe
--- /dev/null
+++ b/sbt-app/src/sbt-test/run/daemon-exit/build.sbt
@@ -0,0 +1 @@
+run / fork := true

From 152fe61cedb6b915e9563e013fd7f0c17ecdae97 Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Fri, 3 Oct 2025 07:24:53 +0900
Subject: [PATCH 07/17] fix runMain task. support JEP-512

---
 run/src/main/scala/sbt/Run.scala              | 29 +++++++--
 .../src/sbt-test/run/jep-512/{ => a1}/A.scala |  0
 sbt-app/src/sbt-test/run/jep-512/a2/A.java    |  7 +++
 sbt-app/src/sbt-test/run/jep-512/a3/A.java    |  7 +++
 sbt-app/src/sbt-test/run/jep-512/a4/A.java    |  7 +++
 sbt-app/src/sbt-test/run/jep-512/a5/A.java    |  7 +++
 sbt-app/src/sbt-test/run/jep-512/a6/A.java    |  3 +
 sbt-app/src/sbt-test/run/jep-512/build.sbt    | 59 ++++++++++++++++---
 sbt-app/src/sbt-test/run/jep-512/test         |  7 ++-
 9 files changed, 113 insertions(+), 13 deletions(-)
 rename sbt-app/src/sbt-test/run/jep-512/{ => a1}/A.scala (100%)
 create mode 100644 sbt-app/src/sbt-test/run/jep-512/a2/A.java
 create mode 100644 sbt-app/src/sbt-test/run/jep-512/a3/A.java
 create mode 100644 sbt-app/src/sbt-test/run/jep-512/a4/A.java
 create mode 100644 sbt-app/src/sbt-test/run/jep-512/a5/A.java
 create mode 100644 sbt-app/src/sbt-test/run/jep-512/a6/A.java

diff --git a/run/src/main/scala/sbt/Run.scala b/run/src/main/scala/sbt/Run.scala
index f964d9b4b..c68bb830a 100644
--- a/run/src/main/scala/sbt/Run.scala
+++ b/run/src/main/scala/sbt/Run.scala
@@ -10,7 +10,7 @@ package sbt
 
 import java.io.File
 import java.lang.reflect.Method
-import java.lang.reflect.Modifier.{ isPublic, isStatic }
+import java.lang.reflect.Modifier.{ isPrivate, isPublic, isStatic }
 import sbt.internal.inc.ScalaInstance
 import sbt.internal.inc.classpath.{ ClasspathFilter, ClasspathUtil }
 import sbt.internal.util.MessageOnlyException
@@ -133,10 +133,17 @@ class Run(private[sbt] val newLoader: Seq[File] => ClassLoader, trapExit: Boolea
     currentThread.setContextClassLoader(loader)
     try {
       if (main.isStatic) {
+        if (Run.isJava25Plus) {
+          main.method.setAccessible(true)
+        }
         if (main.parameterCount > 0) main.method.invoke(null, options.toArray[String])
         else main.method.invoke(null)
       } else {
-        val ref = main.mainClass.getDeclaredConstructor().newInstance().asInstanceOf[AnyRef]
+        val constructor = main.mainClass.getDeclaredConstructor()
+        if (Run.isJava25Plus) {
+          constructor.setAccessible(true)
+        }
+        val ref = constructor.newInstance().asInstanceOf[AnyRef]
         if (main.parameterCount > 0) main.method.invoke(ref, options.toArray[String])
         else main.method.invoke(ref)
       }
@@ -165,10 +172,24 @@ class Run(private[sbt] val newLoader: Seq[File] => ClassLoader, trapExit: Boolea
       val method = try {
         mainClass.getMethod("main", classOf[Array[String]])
       } catch {
-        case _: NoSuchMethodException => mainClass.getMethod("main")
+        case _: NoSuchMethodException =>
+          try {
+            mainClass.getMethod("main")
+          } catch {
+            case _: NoSuchMethodException =>
+              try {
+                mainClass.getDeclaredMethod("main", classOf[Array[String]])
+              } catch {
+                case _: NoSuchMethodException =>
+                  mainClass.getDeclaredMethod("main")
+              }
+          }
+      }
+      val modifiers = method.getModifiers
+      if (isPrivate(modifiers)) {
+        throw new NoSuchMethodException(s"${mainClassName}.main is private")
       }
       method.setAccessible(true)
-      val modifiers = method.getModifiers
       DetectedMain(mainClass, method, isStatic(modifiers), method.getParameterCount())
     } else {
       val method = mainClass.getMethod("main", classOf[Array[String]])
diff --git a/sbt-app/src/sbt-test/run/jep-512/A.scala b/sbt-app/src/sbt-test/run/jep-512/a1/A.scala
similarity index 100%
rename from sbt-app/src/sbt-test/run/jep-512/A.scala
rename to sbt-app/src/sbt-test/run/jep-512/a1/A.scala
diff --git a/sbt-app/src/sbt-test/run/jep-512/a2/A.java b/sbt-app/src/sbt-test/run/jep-512/a2/A.java
new file mode 100644
index 000000000..cb51194e0
--- /dev/null
+++ b/sbt-app/src/sbt-test/run/jep-512/a2/A.java
@@ -0,0 +1,7 @@
+package example;
+
+class A {
+  void main() {
+    System.out.println("package private no args");
+  }
+}
diff --git a/sbt-app/src/sbt-test/run/jep-512/a3/A.java b/sbt-app/src/sbt-test/run/jep-512/a3/A.java
new file mode 100644
index 000000000..c1d2792cb
--- /dev/null
+++ b/sbt-app/src/sbt-test/run/jep-512/a3/A.java
@@ -0,0 +1,7 @@
+package example;
+
+class A {
+  protected void main() {
+    System.out.println("protected no args");
+  }
+}
diff --git a/sbt-app/src/sbt-test/run/jep-512/a4/A.java b/sbt-app/src/sbt-test/run/jep-512/a4/A.java
new file mode 100644
index 000000000..6b646c14f
--- /dev/null
+++ b/sbt-app/src/sbt-test/run/jep-512/a4/A.java
@@ -0,0 +1,7 @@
+package example;
+
+class A {
+  void main(String[] args) {
+    System.out.println("package private with args");
+  }
+}
diff --git a/sbt-app/src/sbt-test/run/jep-512/a5/A.java b/sbt-app/src/sbt-test/run/jep-512/a5/A.java
new file mode 100644
index 000000000..bb441141a
--- /dev/null
+++ b/sbt-app/src/sbt-test/run/jep-512/a5/A.java
@@ -0,0 +1,7 @@
+package example;
+
+class A {
+  private void main(String[] args) {
+    System.out.println("private");
+  }
+}
diff --git a/sbt-app/src/sbt-test/run/jep-512/a6/A.java b/sbt-app/src/sbt-test/run/jep-512/a6/A.java
new file mode 100644
index 000000000..7ce4a32e7
--- /dev/null
+++ b/sbt-app/src/sbt-test/run/jep-512/a6/A.java
@@ -0,0 +1,3 @@
+void main() {
+  IO.println("compact source file with java.lang.IO");
+}
diff --git a/sbt-app/src/sbt-test/run/jep-512/build.sbt b/sbt-app/src/sbt-test/run/jep-512/build.sbt
index e46b37039..3adcc19ef 100644
--- a/sbt-app/src/sbt-test/run/jep-512/build.sbt
+++ b/sbt-app/src/sbt-test/run/jep-512/build.sbt
@@ -1,11 +1,54 @@
-// 2.12.x uses Zinc's compiler bridge
-ThisBuild / scalaVersion := "2.12.20"
-
 @transient
 lazy val check = taskKey[Unit]("")
 
-check := {
-  if (scala.util.Properties.isJavaAtLeast("25"))
-    (Compile / run).toTask(" ").value
-  else ()
-}
+lazy val common = Def.settings(
+  // 2.12.x uses Zinc's compiler bridge
+  scalaVersion := "2.12.20",
+)
+
+// use `runMain` instead of `run` because discoveredMainClasses return empty
+// if JEP-512 java main method
+// TODO fix zinc
+// https://github.com/sbt/sbt/issues/7384#issuecomment-3361020003
+lazy val commonRunMainCheck = Def.settings(
+  check := {
+    if (scala.util.Properties.isJavaAtLeast("25")) {
+      (Compile / runMain).toTask(" example.A").value
+    } else ()
+  }
+)
+
+lazy val a1 = project
+  .settings(common)
+  .settings(
+    check := {
+      if (scala.util.Properties.isJavaAtLeast("25")) {
+        assert((Compile / discoveredMainClasses).value.size == 1)
+        (Compile / run).toTask(" ").value
+      } else ()
+    }
+  )
+
+lazy val a2 = project.settings(common, commonRunMainCheck)
+lazy val a3 = project.settings(common, commonRunMainCheck)
+lazy val a4 = project.settings(common, commonRunMainCheck)
+
+lazy val a5 = project.settings(
+  common,
+  check := {
+    if (scala.util.Properties.isJavaAtLeast("25")) {
+      (Compile / runMain).toTask(" example.A").value
+    } else {
+      sys.error("not jdk 25")
+    }
+  }
+)
+
+lazy val a6 = project.settings(
+  common,
+  check := {
+    if (scala.util.Properties.isJavaAtLeast("25")) {
+      (Compile / runMain).toTask(" A").value
+    } else ()
+  }
+)
diff --git a/sbt-app/src/sbt-test/run/jep-512/test b/sbt-app/src/sbt-test/run/jep-512/test
index c28fe4985..9fbd123fa 100644
--- a/sbt-app/src/sbt-test/run/jep-512/test
+++ b/sbt-app/src/sbt-test/run/jep-512/test
@@ -1,2 +1,7 @@
 # > run
-> check
+> a1/check
+> a2/check
+> a3/check
+> a4/check
+-> a5/check
+> a6/check

From 1e6afc58c4358478297cc8833f735943d7a55fa4 Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Sun, 5 Oct 2025 14:21:40 -0400
Subject: [PATCH 08/17] Update to lm 1.11.6

---
 project/Dependencies.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 17e157653..ccb7edda0 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -14,7 +14,7 @@ object Dependencies {
   // sbt modules
   private val ioVersion = nightlyVersion.getOrElse("1.10.5")
   private val lmVersion =
-    sys.props.get("sbt.build.lm.version").orElse(nightlyVersion).getOrElse("1.11.5")
+    sys.props.get("sbt.build.lm.version").orElse(nightlyVersion).getOrElse("1.11.6")
   val zincVersion = nightlyVersion.getOrElse("1.11.0")
 
   private val sbtIO = "org.scala-sbt" %% "io" % ioVersion

From 9d2a5f478bde5d45562423cb6decf92b255b9517 Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Sun, 5 Oct 2025 14:57:23 -0400
Subject: [PATCH 09/17] sbt 1.11.7

---
 build.sbt | 2 +-
 sbt       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/build.sbt b/build.sbt
index 70ed6f40f..a028802da 100644
--- a/build.sbt
+++ b/build.sbt
@@ -11,7 +11,7 @@ import scala.util.Try
 // ThisBuild settings take lower precedence,
 // but can be shared across the multi projects.
 ThisBuild / version := {
-  val v = "1.11.7-SNAPSHOT"
+  val v = "1.11.8-SNAPSHOT"
   nightlyVersion.getOrElse(v)
 }
 ThisBuild / version2_13 := "2.0.0-SNAPSHOT"
diff --git a/sbt b/sbt
index 7f03aa622..aa12e7446 100755
--- a/sbt
+++ b/sbt
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 set +e
-declare builtin_sbt_version="1.11.6"
+declare builtin_sbt_version="1.11.7"
 declare -a residual_args
 declare -a java_args
 declare -a scalac_args

From 49c83060914e0c20ea912231da779dbc569a880e Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Thu, 23 Oct 2025 15:20:52 +0900
Subject: [PATCH 10/17] Update semanticdbVersion

---
 build.sbt                                              | 2 +-
 main/src/main/scala/sbt/plugins/SemanticdbPlugin.scala | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/build.sbt b/build.sbt
index a028802da..f10004658 100644
--- a/build.sbt
+++ b/build.sbt
@@ -48,7 +48,7 @@ ThisBuild / libraryDependencySchemes += "org.scala-lang.modules" %% "scala-xml"
 
 Global / semanticdbEnabled := !(Global / insideCI).value
 // Change main/src/main/scala/sbt/plugins/SemanticdbPlugin.scala too, if you change this.
-Global / semanticdbVersion := "4.9.9"
+Global / semanticdbVersion := "4.14.1"
 val excludeLint = SettingKey[Set[Def.KeyedInitialize[_]]]("excludeLintKeys")
 Global / excludeLint := (Global / excludeLint).?.value.getOrElse(Set.empty)
 Global / excludeLint += componentID
diff --git a/main/src/main/scala/sbt/plugins/SemanticdbPlugin.scala b/main/src/main/scala/sbt/plugins/SemanticdbPlugin.scala
index 46a018397..040d5bbf8 100644
--- a/main/src/main/scala/sbt/plugins/SemanticdbPlugin.scala
+++ b/main/src/main/scala/sbt/plugins/SemanticdbPlugin.scala
@@ -27,7 +27,7 @@ object SemanticdbPlugin extends AutoPlugin {
     semanticdbEnabled := SysProp.semanticdb,
     semanticdbIncludeInJar := false,
     semanticdbOptions := List(),
-    semanticdbVersion := "4.9.9"
+    semanticdbVersion := "4.14.1"
   )
 
   override lazy val projectSettings: Seq[Def.Setting[_]] = Seq(

From e42c54f7820c09454688a8319a7697d7643d67b9 Mon Sep 17 00:00:00 2001
From: danicheg <esik.danny@gmail.com>
Date: Thu, 30 Oct 2025 11:30:06 +0300
Subject: [PATCH 11/17] [1.x] Update scala213 to 2.13.17

---
 project/Dependencies.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index ccb7edda0..c14030431 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -5,7 +5,7 @@ import sbt.contraband.ContrabandPlugin.autoImport._
 object Dependencies {
   // WARNING: Please Scala update versions in PluginCross.scala too
   val scala212 = "2.12.20"
-  val scala213 = "2.13.16"
+  val scala213 = "2.13.17"
   val checkPluginCross = settingKey[Unit]("Make sure scalaVersion match up")
   val baseScalaVersion = scala212
   def nightlyVersion: Option[String] =

From ed7da85ef012b71919c8ce35b5e46c760db7766a Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Sat, 1 Nov 2025 14:53:58 -0400
Subject: [PATCH 12/17] Backport Compiler

Backport scala.internal.Compiler from sbt 2.x so we can merge easier.
---
 main/src/main/scala/sbt/Defaults.scala        | 178 +------------
 .../main/scala/sbt/internal/Compiler.scala    | 234 ++++++++++++++++++
 2 files changed, 243 insertions(+), 169 deletions(-)
 create mode 100644 main/src/main/scala/sbt/internal/Compiler.scala

diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index fd49fdcc3..a6c2c5a56 100644
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -689,7 +689,7 @@ object Defaults extends BuildCommon {
       }
       else topLoader
     },
-    scalaInstance := scalaInstanceTask.value,
+    scalaInstance := Compiler.scalaInstanceTask.value,
     crossVersion := (if (crossPaths.value) CrossVersion.binary else CrossVersion.disabled),
     pluginCrossBuild / sbtBinaryVersion := binarySbtVersion(
       (pluginCrossBuild / sbtVersion).value
@@ -1139,34 +1139,8 @@ object Defaults extends BuildCommon {
       }
     }
 
-  def scalaInstanceTask: Initialize[Task[ScalaInstance]] = Def.taskDyn {
-    // if this logic changes, ensure that `unmanagedScalaInstanceOnly` and `update` are changed
-    //  appropriately to avoid cycles
-    scalaHome.value match {
-      case Some(h) => scalaInstanceFromHome(h)
-      case None =>
-        val scalaProvider = appConfiguration.value.provider.scalaProvider
-        val version = scalaVersion.value
-        if (version == scalaProvider.version) // use the same class loader as the Scala classes used by sbt
-          Def.task {
-            val allJars = scalaProvider.jars
-            val libraryJars = allJars.filter(_.getName == "scala-library.jar")
-            allJars.filter(_.getName == "scala-compiler.jar") match {
-              case Array(compilerJar) if libraryJars.nonEmpty =>
-                makeScalaInstance(
-                  version,
-                  libraryJars,
-                  allJars,
-                  Seq.empty,
-                  state.value,
-                  scalaInstanceTopLoader.value
-                )
-              case _ => ScalaInstance(version, scalaProvider)
-            }
-          } else
-          scalaInstanceFromUpdate
-    }
-  }
+  @deprecated("Use Compiler.scalaInstanceTask", "1.12.0")
+  def scalaInstanceTask: Initialize[Task[ScalaInstance]] = Compiler.scalaInstanceTask
 
   // Returns the ScalaInstance only if it was not constructed via `update`
   //  This is necessary to prevent cycles between `update` and `scalaInstance`
@@ -1175,108 +1149,9 @@ object Defaults extends BuildCommon {
       if (scalaHome.value.isDefined) Def.task(Some(scalaInstance.value)) else Def.task(None)
     }
 
-  private[this] def noToolConfiguration(autoInstance: Boolean): String = {
-    val pre = "Missing Scala tool configuration from the 'update' report.  "
-    val post =
-      if (autoInstance)
-        "'scala-tool' is normally added automatically, so this may indicate a bug in sbt or you may be removing it from ivyConfigurations, for example."
-      else
-        "Explicitly define scalaInstance or scalaHome or include Scala dependencies in the 'scala-tool' configuration."
-    pre + post
-  }
+  def scalaInstanceFromUpdate: Initialize[Task[ScalaInstance]] =
+    Compiler.scalaInstanceFromUpdate
 
-  def scalaInstanceFromUpdate: Initialize[Task[ScalaInstance]] = Def.task {
-    val sv = scalaVersion.value
-    val fullReport = update.value
-    val s = streams.value
-
-    // For Scala 3, update scala-library.jar in `scala-tool` and `scala-doc-tool` in case a newer version
-    // is present in the `compile` configuration. This is needed once forwards binary compatibility is dropped
-    // to avoid NoSuchMethod exceptions when expanding macros.
-    def updateLibraryToCompileConfiguration(report: ConfigurationReport) =
-      if (!ScalaArtifacts.isScala3(sv)) report
-      else
-        (for {
-          compileConf <- fullReport.configuration(Configurations.Compile)
-          compileLibMod <- compileConf.modules.find(_.module.name == ScalaArtifacts.LibraryID)
-          reportLibMod <- report.modules.find(_.module.name == ScalaArtifacts.LibraryID)
-          if VersionNumber(reportLibMod.module.revision)
-            .matchesSemVer(SemanticSelector(s"<${compileLibMod.module.revision}"))
-        } yield {
-          val newMods = report.modules
-            .filterNot(_.module.name == ScalaArtifacts.LibraryID) :+ compileLibMod
-          report.withModules(newMods)
-        }).getOrElse(report)
-
-    val toolReport = updateLibraryToCompileConfiguration(
-      fullReport
-        .configuration(Configurations.ScalaTool)
-        .getOrElse(sys.error(noToolConfiguration(managedScalaInstance.value)))
-    )
-
-    if (Classpaths.isScala213(sv)) {
-      val scalaDeps = for {
-        compileReport <- fullReport.configuration(Configurations.Compile).iterator
-        libName <- ScalaArtifacts.Artifacts.iterator
-        lib <- compileReport.modules.find(_.module.name == libName)
-      } yield lib
-      for (lib <- scalaDeps.take(1)) {
-        val libVer = lib.module.revision
-        val libName = lib.module.name
-        val proj = Def.displayBuildRelative(thisProjectRef.value.build, thisProjectRef.value)
-        if (VersionNumber(sv).matchesSemVer(SemanticSelector(s"<$libVer"))) {
-          val err = !allowUnsafeScalaLibUpgrade.value
-          val fix =
-            if (err)
-              """Upgrade the `scalaVersion` to fix the build. If upgrading the Scala compiler version is
-                |not possible (for example due to a regression in the compiler or a missing dependency),
-                |this error can be demoted by setting `allowUnsafeScalaLibUpgrade := true`.""".stripMargin
-            else
-              s"""Note that the dependency classpath and the runtime classpath of your project
-                 |contain the newer $libName $libVer, even if the scalaVersion is $sv.
-                 |Compilation (macro expansion) or using the Scala REPL in sbt may fail with a LinkageError.""".stripMargin
-
-          val msg =
-            s"""Expected `$proj scalaVersion` to be $libVer or later, but found $sv.
-               |To support backwards-only binary compatibility (SIP-51), the Scala 2.13 compiler
-               |should not be older than $libName on the dependency classpath.
-               |
-               |$fix
-               |
-               |See `$proj evicted` to know why $libName $libVer is getting pulled in.
-               |""".stripMargin
-          if (err) sys.error(msg)
-          else s.log.warn(msg)
-        }
-      }
-    }
-    def file(id: String): File = {
-      val files = for {
-        m <- toolReport.modules if m.module.name.startsWith(id)
-        (art, file) <- m.artifacts if art.`type` == Artifact.DefaultType
-      } yield file
-      files.headOption getOrElse sys.error(s"Missing $id jar file")
-    }
-
-    val allCompilerJars = toolReport.modules.flatMap(_.artifacts.map(_._2))
-    val allDocJars =
-      fullReport
-        .configuration(Configurations.ScalaDocTool)
-        .map(updateLibraryToCompileConfiguration)
-        .toSeq
-        .flatMap(_.modules)
-        .flatMap(_.artifacts.map(_._2))
-    val libraryJars = ScalaArtifacts.libraryIds(sv).map(file)
-
-    makeScalaInstance(
-      sv,
-      libraryJars,
-      allCompilerJars,
-      allDocJars,
-      state.value,
-      scalaInstanceTopLoader.value,
-    )
-  }
   def makeScalaInstance(
       version: String,
       libraryJars: Array[File],
@@ -1284,46 +1159,11 @@ object Defaults extends BuildCommon {
       allDocJars: Seq[File],
       state: State,
       topLoader: ClassLoader,
-  ): ScalaInstance = {
-    val classLoaderCache = state.extendedClassLoaderCache
-    val compilerJars = allCompilerJars.filterNot(libraryJars.contains).distinct.toArray
-    val docJars = allDocJars
-      .filterNot(jar => libraryJars.contains(jar) || compilerJars.contains(jar))
-      .distinct
-      .toArray
-    val allJars = libraryJars ++ compilerJars ++ docJars
+  ): ScalaInstance =
+    Compiler.makeScalaInstance(version, libraryJars, allCompilerJars, allDocJars, state, topLoader)
 
-    val libraryLoader = classLoaderCache(libraryJars.toList, topLoader)
-    val compilerLoader = classLoaderCache(compilerJars.toList, libraryLoader)
-    val fullLoader =
-      if (docJars.isEmpty) compilerLoader
-      else classLoaderCache(docJars.distinct.toList, compilerLoader)
-    new ScalaInstance(
-      version = version,
-      loader = fullLoader,
-      loaderCompilerOnly = compilerLoader,
-      loaderLibraryOnly = libraryLoader,
-      libraryJars = libraryJars,
-      compilerJars = compilerJars,
-      allJars = allJars,
-      explicitActual = Some(version)
-    )
-  }
-  def scalaInstanceFromHome(dir: File): Initialize[Task[ScalaInstance]] = Def.task {
-    val dummy = ScalaInstance(dir)(state.value.classLoaderCache.apply)
-    Seq(dummy.loader, dummy.loaderLibraryOnly).foreach {
-      case a: AutoCloseable => a.close()
-      case _                =>
-    }
-    makeScalaInstance(
-      dummy.version,
-      dummy.libraryJars,
-      dummy.compilerJars,
-      dummy.allJars,
-      state.value,
-      scalaInstanceTopLoader.value,
-    )
-  }
+  def scalaInstanceFromHome(dir: File): Initialize[Task[ScalaInstance]] =
+    Compiler.scalaInstanceFromHome(dir)
 
   private[this] def testDefaults =
     Defaults.globalDefaults(
diff --git a/main/src/main/scala/sbt/internal/Compiler.scala b/main/src/main/scala/sbt/internal/Compiler.scala
new file mode 100644
index 000000000..d52b33db5
--- /dev/null
+++ b/main/src/main/scala/sbt/internal/Compiler.scala
@@ -0,0 +1,234 @@
+/*
+ * sbt
+ * Copyright 2011 - 2018, Lightbend, Inc.
+ * Copyright 2008 - 2010, Mark Harrah
+ * Licensed under Apache License 2.0 (see LICENSE)
+ */
+
+package sbt
+package internal
+
+import java.io.File
+import sbt.internal.inc.ScalaInstance
+import sbt.librarymanagement.{
+  Artifact,
+  Configurations,
+  ConfigurationReport,
+  ScalaArtifacts,
+  SemanticSelector,
+  VersionNumber
+}
+import xsbti.ScalaProvider
+
+private[sbt] object Compiler {
+  def scalaInstanceTask: Def.Initialize[Task[ScalaInstance]] =
+    Def.taskDyn {
+      val sh = Keys.scalaHome.value
+      val app = Keys.appConfiguration.value
+      val managed = Keys.managedScalaInstance.value
+      val sv = Keys.scalaVersion.value
+      // if this logic changes, ensure that `unmanagedScalaInstanceOnly` and `update` are changed
+      //  appropriately to avoid cycles
+      sh match {
+        case Some(h) => scalaInstanceFromHome(h)
+        case _ =>
+          val scalaProvider = app.provider.scalaProvider
+          if (!managed) emptyScalaInstance
+          else if (sv == scalaProvider.version) optimizedScalaInstance(sv, scalaProvider)
+          else scalaInstanceFromUpdate
+      }
+    }
+
+  /**
+   * A dummy ScalaInstance for Java-only projects.
+   */
+  def emptyScalaInstance: Def.Initialize[Task[ScalaInstance]] = Def.task {
+    makeScalaInstance(
+      "0.0.0",
+      Array.empty,
+      Seq.empty,
+      Seq.empty,
+      Keys.state.value,
+      Keys.scalaInstanceTopLoader.value,
+    )
+  }
+
+  // Use the same class loader as the Scala classes used by sbt
+  def optimizedScalaInstance(
+      sv: String,
+      scalaProvider: ScalaProvider
+  ): Def.Initialize[Task[ScalaInstance]] = Def.task {
+    val allJars = scalaProvider.jars
+    val libraryJars = allJars.filter { jar =>
+      jar.getName == "scala-library.jar" || jar.getName.startsWith("scala3-library_3")
+    }
+    val compilerJar = allJars.filter { jar =>
+      jar.getName == "scala-compiler.jar" || jar.getName.startsWith("scala3-compiler_3")
+    }
+    compilerJar match {
+      case Array(compilerJar) if libraryJars.nonEmpty =>
+        makeScalaInstance(
+          sv,
+          libraryJars,
+          allJars.toSeq,
+          Seq.empty,
+          Keys.state.value,
+          Keys.scalaInstanceTopLoader.value,
+        )
+      case _ => ScalaInstance(sv, scalaProvider)
+    }
+  }
+
+  def scalaInstanceFromHome(dir: File): Def.Initialize[Task[ScalaInstance]] = Def.task {
+    val dummy = ScalaInstance(dir)(Keys.state.value.classLoaderCache.apply)
+    Seq(dummy.loader, dummy.loaderLibraryOnly).foreach {
+      case a: AutoCloseable => a.close()
+      case _                =>
+    }
+    makeScalaInstance(
+      dummy.version,
+      dummy.libraryJars,
+      dummy.compilerJars.toSeq,
+      dummy.allJars.toSeq,
+      Keys.state.value,
+      Keys.scalaInstanceTopLoader.value,
+    )
+  }
+
+  def scalaInstanceFromUpdate: Def.Initialize[Task[ScalaInstance]] = Def.task {
+    val sv = Keys.scalaVersion.value
+    val fullReport = Keys.update.value
+    val s = Keys.streams.value
+
+    // For Scala 3, update scala-library.jar in `scala-tool` and `scala-doc-tool` in case a newer version
+    // is present in the `compile` configuration. This is needed once forwards binary compatibility is dropped
+    // to avoid NoSuchMethod exceptions when expanding macros.
+    def updateLibraryToCompileConfiguration(report: ConfigurationReport) =
+      if (!ScalaArtifacts.isScala3(sv)) report
+      else
+        (for {
+          compileConf <- fullReport.configuration(Configurations.Compile)
+          compileLibMod <- compileConf.modules.find(_.module.name == ScalaArtifacts.LibraryID)
+          reportLibMod <- report.modules.find(_.module.name == ScalaArtifacts.LibraryID)
+          if VersionNumber(reportLibMod.module.revision)
+            .matchesSemVer(SemanticSelector(s"<${compileLibMod.module.revision}"))
+        } yield {
+          val newMods = report.modules
+            .filterNot(_.module.name == ScalaArtifacts.LibraryID) :+ compileLibMod
+          report.withModules(newMods)
+        }).getOrElse(report)
+
+    val toolReport = updateLibraryToCompileConfiguration(
+      fullReport
+        .configuration(Configurations.ScalaTool)
+        .getOrElse(sys.error(noToolConfiguration(Keys.managedScalaInstance.value)))
+    )
+
+    if (Classpaths.isScala213(sv)) {
+      val scalaDeps = for {
+        compileReport <- fullReport.configuration(Configurations.Compile).iterator
+        libName <- ScalaArtifacts.Artifacts.iterator
+        lib <- compileReport.modules.find(_.module.name == libName)
+      } yield lib
+      for (lib <- scalaDeps.take(1)) {
+        val libVer = lib.module.revision
+        val libName = lib.module.name
+        val proj =
+          Def.displayBuildRelative(Keys.thisProjectRef.value.build, Keys.thisProjectRef.value)
+        if (VersionNumber(sv).matchesSemVer(SemanticSelector(s"<$libVer"))) {
+          val err = !Keys.allowUnsafeScalaLibUpgrade.value
+          val fix =
+            if (err)
+              """Upgrade the `scalaVersion` to fix the build. If upgrading the Scala compiler version is
+                |not possible (for example due to a regression in the compiler or a missing dependency),
+                |this error can be demoted by setting `allowUnsafeScalaLibUpgrade := true`.""".stripMargin
+            else
+              s"""Note that the dependency classpath and the runtime classpath of your project
+                 |contain the newer $libName $libVer, even if the scalaVersion is $sv.
+                 |Compilation (macro expansion) or using the Scala REPL in sbt may fail with a LinkageError.""".stripMargin
+
+          val msg =
+            s"""Expected `$proj scalaVersion` to be $libVer or later, but found $sv.
+               |To support backwards-only binary compatibility (SIP-51), the Scala 2.13 compiler
+               |should not be older than $libName on the dependency classpath.
+               |
+               |$fix
+               |
+               |See `$proj evicted` to know why $libName $libVer is getting pulled in.
+               |""".stripMargin
+          if (err) sys.error(msg)
+          else s.log.warn(msg)
+        }
+      }
+    }
+    def file(id: String): File = {
+      val files = for {
+        m <- toolReport.modules if m.module.name.startsWith(id)
+        (art, file) <- m.artifacts if art.`type` == Artifact.DefaultType
+      } yield file
+      files.headOption getOrElse sys.error(s"Missing $id jar file")
+    }
+
+    val allCompilerJars = toolReport.modules.flatMap(_.artifacts.map(_._2))
+    val allDocJars =
+      fullReport
+        .configuration(Configurations.ScalaDocTool)
+        .map(updateLibraryToCompileConfiguration)
+        .toSeq
+        .flatMap(_.modules)
+        .flatMap(_.artifacts.map(_._2))
+    val libraryJars = ScalaArtifacts.libraryIds(sv).map(file)
+
+    makeScalaInstance(
+      sv,
+      libraryJars,
+      allCompilerJars,
+      allDocJars,
+      Keys.state.value,
+      Keys.scalaInstanceTopLoader.value,
+    )
+  }
+
+  def makeScalaInstance(
+      version: String,
+      libraryJars: Array[File],
+      allCompilerJars: Seq[File],
+      allDocJars: Seq[File],
+      state: State,
+      topLoader: ClassLoader,
+  ): ScalaInstance = {
+    val classLoaderCache = state.extendedClassLoaderCache
+    val compilerJars = allCompilerJars.filterNot(libraryJars.contains).distinct.toArray
+    val docJars = allDocJars
+      .filterNot(jar => libraryJars.contains(jar) || compilerJars.contains(jar))
+      .distinct
+      .toArray
+    val allJars = libraryJars ++ compilerJars ++ docJars
+
+    val libraryLoader = classLoaderCache(libraryJars.toList, topLoader)
+    val compilerLoader = classLoaderCache(compilerJars.toList, libraryLoader)
+    val fullLoader =
+      if (docJars.isEmpty) compilerLoader
+      else classLoaderCache(docJars.distinct.toList, compilerLoader)
+    new ScalaInstance(
+      version = version,
+      loader = fullLoader,
+      loaderCompilerOnly = compilerLoader,
+      loaderLibraryOnly = libraryLoader,
+      libraryJars = libraryJars,
+      compilerJars = compilerJars,
+      allJars = allJars,
+      explicitActual = Some(version)
+    )
+  }
+
+  private def noToolConfiguration(autoInstance: Boolean): String = {
+    val pre = "Missing Scala tool configuration from the 'update' report.  "
+    val post =
+      if (autoInstance)
+        "'scala-tool' is normally added automatically, so this may indicate a bug in sbt or you may be removing it from ivyConfigurations, for example."
+      else
+        "Explicitly define scalaInstance or scalaHome or include Scala dependencies in the 'scala-tool' configuration."
+    pre + post
+  }
+}

From 840b851445cc1fd4935cb9a0b6167c647589c3db Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Sat, 1 Nov 2025 20:50:01 -0400
Subject: [PATCH 13/17] [1.x] Add Scala 3.8 REPL support

**Problem**
Scala 3.8 REPL won't work since they've split the repl artifact into another JAR.

**Solution**
This works around it by creating a yet-another sandbox configuration ScalaReplTool
(similar to ScalaTool and ScalaDocTool) and a separate scalaInstance for
console task, so when Zinc is invoked we'll be able to conjure the right array of JARs.
---
 build.sbt                                     |   2 +-
 main/src/main/scala/sbt/Defaults.scala        | 190 +++++++++---------
 .../main/scala/sbt/internal/Compiler.scala    | 187 +++++++++--------
 project/Dependencies.scala                    |   4 +-
 4 files changed, 206 insertions(+), 177 deletions(-)

diff --git a/build.sbt b/build.sbt
index f10004658..8f6afffae 100644
--- a/build.sbt
+++ b/build.sbt
@@ -11,7 +11,7 @@ import scala.util.Try
 // ThisBuild settings take lower precedence,
 // but can be shared across the multi projects.
 ThisBuild / version := {
-  val v = "1.11.8-SNAPSHOT"
+  val v = "1.12.0-SNAPSHOT"
   nightlyVersion.getOrElse(v)
 }
 ThisBuild / version2_13 := "2.0.0-SNAPSHOT"
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index a6c2c5a56..1b149e855 100644
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -671,89 +671,94 @@ object Defaults extends BuildCommon {
   )
 
   // This is included into JvmPlugin.projectSettings
-  def compileBase = inTask(console)(compilersSetting :: Nil) ++ compileBaseGlobal ++ Seq(
-    useScalaReplJLine :== false,
-    scalaInstanceTopLoader := {
-      val topLoader = if (!useScalaReplJLine.value) {
-        // the JLineLoader contains the SbtInterfaceClassLoader
-        classOf[org.jline.terminal.Terminal].getClassLoader
-      } else classOf[Compilers].getClassLoader // the SbtInterfaceClassLoader
+  def compileBase =
+    inTask(console)(
+      Seq(
+        scalaInstance := Compiler.scalaInstanceTask(Some(Configurations.ScalaReplTool)).value,
+      ) ++ compilersSetting
+    ) ++ compileBaseGlobal ++ Seq(
+      useScalaReplJLine :== false,
+      scalaInstanceTopLoader := {
+        val topLoader = if (!useScalaReplJLine.value) {
+          // the JLineLoader contains the SbtInterfaceClassLoader
+          classOf[org.jline.terminal.Terminal].getClassLoader
+        } else classOf[Compilers].getClassLoader // the SbtInterfaceClassLoader
 
-      // Scala 2.10 shades jline in the console so we need to make sure that it loads a compatible
-      // jansi version. Because of the shading, console does not work with the thin client for 2.10.x.
-      if (scalaVersion.value.startsWith("2.10.")) new ClassLoader(topLoader) {
-        override protected def loadClass(name: String, resolve: Boolean): Class[_] = {
-          if (name.startsWith("org.fusesource")) throw new ClassNotFoundException(name)
-          super.loadClass(name, resolve)
+        // Scala 2.10 shades jline in the console so we need to make sure that it loads a compatible
+        // jansi version. Because of the shading, console does not work with the thin client for 2.10.x.
+        if (scalaVersion.value.startsWith("2.10.")) new ClassLoader(topLoader) {
+          override protected def loadClass(name: String, resolve: Boolean): Class[_] = {
+            if (name.startsWith("org.fusesource")) throw new ClassNotFoundException(name)
+            super.loadClass(name, resolve)
+          }
         }
-      }
-      else topLoader
-    },
-    scalaInstance := Compiler.scalaInstanceTask.value,
-    crossVersion := (if (crossPaths.value) CrossVersion.binary else CrossVersion.disabled),
-    pluginCrossBuild / sbtBinaryVersion := binarySbtVersion(
-      (pluginCrossBuild / sbtVersion).value
-    ),
-    // Use (sbtVersion in pluginCrossBuild) to pick the sbt module to depend from the plugin.
-    // Because `sbtVersion in pluginCrossBuild` can be scoped to project level,
-    // this setting needs to be set here too.
-    pluginCrossBuild / sbtDependency := {
-      val app = appConfiguration.value
-      val id = app.provider.id
-      val sv = (pluginCrossBuild / sbtVersion).value
-      val scalaV = (pluginCrossBuild / scalaVersion).value
-      val binVersion = (pluginCrossBuild / scalaBinaryVersion).value
-      val cross = id.crossVersionedValue match {
-        case CrossValue.Disabled => Disabled()
-        case CrossValue.Full     => CrossVersion.full
-        case CrossValue.Binary   => CrossVersion.binary
-      }
-      val base = ModuleID(id.groupID, id.name, sv).withCrossVersion(cross)
-      CrossVersion(scalaV, binVersion)(base).withCrossVersion(Disabled())
-    },
-    crossSbtVersions := Vector((pluginCrossBuild / sbtVersion).value),
-    crossTarget := makeCrossTarget(
-      target.value,
-      scalaVersion.value,
-      scalaBinaryVersion.value,
-      (pluginCrossBuild / sbtBinaryVersion).value,
-      sbtPlugin.value,
-      crossPaths.value
-    ),
-    cleanIvy := IvyActions.cleanCachedResolutionCache(ivyModule.value, streams.value.log),
-    clean := {
-      val _ = cleanIvy.value
-      try {
-        val store = AnalysisUtil.staticCachedStore(
-          analysisFile = (Compile / compileAnalysisFile).value.toPath,
-          useTextAnalysis = !(Compile / enableBinaryCompileAnalysis).value,
-          useConsistent = (Compile / enableConsistentCompileAnalysis).value,
-        )
-        store.clearCache()
-      } catch {
-        case NonFatal(_) => ()
-      }
-      clean.value
-    },
-    scalaCompilerBridgeBinaryJar := Def.settingDyn {
-      val sv = scalaVersion.value
-      if (ScalaArtifacts.isScala3(sv) || VersionNumber(sv)
-            .matchesSemVer(SemanticSelector(s"=2.13 >=${ZincLmUtil.scala2SbtBridgeStart}")))
-        fetchBridgeBinaryJarTask(sv)
-      else Def.task[Option[File]](None)
-    }.value,
-    scalaCompilerBridgeSource := ZincLmUtil.getDefaultBridgeSourceModule(scalaVersion.value),
-    auxiliaryClassFiles ++= {
-      if (ScalaArtifacts.isScala3(scalaVersion.value)) List(TastyFiles.instance)
-      else Nil
-    },
-    consoleProject / scalaCompilerBridgeBinaryJar := None,
-    consoleProject / scalaCompilerBridgeSource := ZincLmUtil.getDefaultBridgeSourceModule(
-      appConfiguration.value.provider.scalaProvider.version
-    ),
-    classpathOptions := ClasspathOptionsUtil.noboot(scalaVersion.value),
-    console / classpathOptions := ClasspathOptionsUtil.replNoboot(scalaVersion.value),
-  )
+        else topLoader
+      },
+      scalaInstance := Compiler.scalaInstanceTask(None).value,
+      crossVersion := (if (crossPaths.value) CrossVersion.binary else CrossVersion.disabled),
+      pluginCrossBuild / sbtBinaryVersion := binarySbtVersion(
+        (pluginCrossBuild / sbtVersion).value
+      ),
+      // Use (sbtVersion in pluginCrossBuild) to pick the sbt module to depend from the plugin.
+      // Because `sbtVersion in pluginCrossBuild` can be scoped to project level,
+      // this setting needs to be set here too.
+      pluginCrossBuild / sbtDependency := {
+        val app = appConfiguration.value
+        val id = app.provider.id
+        val sv = (pluginCrossBuild / sbtVersion).value
+        val scalaV = (pluginCrossBuild / scalaVersion).value
+        val binVersion = (pluginCrossBuild / scalaBinaryVersion).value
+        val cross = id.crossVersionedValue match {
+          case CrossValue.Disabled => Disabled()
+          case CrossValue.Full     => CrossVersion.full
+          case CrossValue.Binary   => CrossVersion.binary
+        }
+        val base = ModuleID(id.groupID, id.name, sv).withCrossVersion(cross)
+        CrossVersion(scalaV, binVersion)(base).withCrossVersion(Disabled())
+      },
+      crossSbtVersions := Vector((pluginCrossBuild / sbtVersion).value),
+      crossTarget := makeCrossTarget(
+        target.value,
+        scalaVersion.value,
+        scalaBinaryVersion.value,
+        (pluginCrossBuild / sbtBinaryVersion).value,
+        sbtPlugin.value,
+        crossPaths.value
+      ),
+      cleanIvy := IvyActions.cleanCachedResolutionCache(ivyModule.value, streams.value.log),
+      clean := {
+        val _ = cleanIvy.value
+        try {
+          val store = AnalysisUtil.staticCachedStore(
+            analysisFile = (Compile / compileAnalysisFile).value.toPath,
+            useTextAnalysis = !(Compile / enableBinaryCompileAnalysis).value,
+            useConsistent = (Compile / enableConsistentCompileAnalysis).value,
+          )
+          store.clearCache()
+        } catch {
+          case NonFatal(_) => ()
+        }
+        clean.value
+      },
+      scalaCompilerBridgeBinaryJar := Def.settingDyn {
+        val sv = scalaVersion.value
+        if (ScalaArtifacts.isScala3(sv) || VersionNumber(sv)
+              .matchesSemVer(SemanticSelector(s"=2.13 >=${ZincLmUtil.scala2SbtBridgeStart}")))
+          fetchBridgeBinaryJarTask(sv)
+        else Def.task[Option[File]](None)
+      }.value,
+      scalaCompilerBridgeSource := ZincLmUtil.getDefaultBridgeSourceModule(scalaVersion.value),
+      auxiliaryClassFiles ++= {
+        if (ScalaArtifacts.isScala3(scalaVersion.value)) List(TastyFiles.instance)
+        else Nil
+      },
+      consoleProject / scalaCompilerBridgeBinaryJar := None,
+      consoleProject / scalaCompilerBridgeSource := ZincLmUtil.getDefaultBridgeSourceModule(
+        appConfiguration.value.provider.scalaProvider.version
+      ),
+      classpathOptions := ClasspathOptionsUtil.noboot(scalaVersion.value),
+      console / classpathOptions := ClasspathOptionsUtil.replNoboot(scalaVersion.value),
+    )
   // must be a val: duplication detected by object identity
   private[this] lazy val compileBaseGlobal: Seq[Setting[_]] = globalDefaults(
     Seq(
@@ -1140,7 +1145,7 @@ object Defaults extends BuildCommon {
     }
 
   @deprecated("Use Compiler.scalaInstanceTask", "1.12.0")
-  def scalaInstanceTask: Initialize[Task[ScalaInstance]] = Compiler.scalaInstanceTask
+  def scalaInstanceTask: Initialize[Task[ScalaInstance]] = Compiler.scalaInstanceTask(None)
 
   // Returns the ScalaInstance only if it was not constructed via `update`
   //  This is necessary to prevent cycles between `update` and `scalaInstance`
@@ -1149,8 +1154,9 @@ object Defaults extends BuildCommon {
       if (scalaHome.value.isDefined) Def.task(Some(scalaInstance.value)) else Def.task(None)
     }
 
+  @deprecated("Use Compiler.scalaInstanceFromUpdate", "1.12.0")
   def scalaInstanceFromUpdate: Initialize[Task[ScalaInstance]] =
-    Compiler.scalaInstanceFromUpdate
+    Compiler.scalaInstanceFromUpdate(None)
 
   def makeScalaInstance(
       version: String,
@@ -2062,6 +2068,7 @@ object Defaults extends BuildCommon {
   def docTaskSettings(key: TaskKey[File] = doc): Seq[Setting[_]] =
     inTask(key)(
       Seq(
+        scalaInstance := Compiler.scalaInstanceTask(Some(Configurations.ScalaDocTool)).value,
         apiMappings ++= {
           val dependencyCp = dependencyClasspath.value
           val log = streams.value.log
@@ -2139,7 +2146,7 @@ object Defaults extends BuildCommon {
           }
           out
         }
-      )
+      ) ++ compilersSetting
     )
 
   def mainBgRunTask = mainBgRunTaskForConfig(Select(Runtime))
@@ -3189,7 +3196,7 @@ object Classpaths {
     ivyConfigurations ++= Configurations.auxiliary,
     ivyConfigurations ++= {
       if (managedScalaInstance.value && scalaHome.value.isEmpty)
-        Configurations.ScalaTool :: Configurations.ScalaDocTool :: Nil
+        Configurations.ScalaTool :: Configurations.ScalaDocTool :: Configurations.ScalaReplTool :: Nil
       else Nil
     },
     // Coursier needs these
@@ -3385,17 +3392,18 @@ object Classpaths {
       val pluginAdjust =
         if (isPlugin) sbtdeps +: base
         else base
-      val sbtOrg = scalaOrganization.value
+      val scalaOrg = scalaOrganization.value
       val version = scalaVersion.value
-      val extResolvers = externalResolvers.value
       val isScala3M123 = ScalaArtifacts.isScala3M123(version)
       val allToolDeps =
         if (scalaHome.value.isDefined || scalaModuleInfo.value.isEmpty || !managedScalaInstance.value)
           Nil
-        else if (!isScala3M123 || extResolvers.contains(Resolver.JCenterRepository)) {
-          ScalaArtifacts.toolDependencies(sbtOrg, version) ++
-            ScalaArtifacts.docToolDependencies(sbtOrg, version)
-        } else ScalaArtifacts.toolDependencies(sbtOrg, version)
+        else if (isScala3M123)
+          ScalaArtifacts.toolDependencies(scalaOrg, version)
+        else
+          ScalaArtifacts.toolDependencies(scalaOrg, version) ++
+            ScalaArtifacts.docToolDependencies(scalaOrg, version) ++
+            ScalaArtifacts.replToolDependencies(scalaOrg, version)
       allToolDeps ++ pluginAdjust
     },
     // in case of meta build, exclude all sbt modules from the dependency graph, so we can use the sbt resolved by the launcher
diff --git a/main/src/main/scala/sbt/internal/Compiler.scala b/main/src/main/scala/sbt/internal/Compiler.scala
index d52b33db5..473e10137 100644
--- a/main/src/main/scala/sbt/internal/Compiler.scala
+++ b/main/src/main/scala/sbt/internal/Compiler.scala
@@ -1,6 +1,7 @@
 /*
  * sbt
- * Copyright 2011 - 2018, Lightbend, Inc.
+ * Copyright 2023, Scala center
+ * Copyright 2011 - 2022, Lightbend, Inc.
  * Copyright 2008 - 2010, Mark Harrah
  * Licensed under Apache License 2.0 (see LICENSE)
  */
@@ -12,16 +13,23 @@ import java.io.File
 import sbt.internal.inc.ScalaInstance
 import sbt.librarymanagement.{
   Artifact,
+  Configuration,
   Configurations,
   ConfigurationReport,
   ScalaArtifacts,
   SemanticSelector,
+  UpdateReport,
   VersionNumber
 }
 import xsbti.ScalaProvider
 
 private[sbt] object Compiler {
-  def scalaInstanceTask: Def.Initialize[Task[ScalaInstance]] =
+
+  /**
+   * Returns a ScalaInstance.
+   * extraToolConf is used for Scala 3 since it started splitting up scaladoc and repl.
+   */
+  def scalaInstanceTask(extraToolConf: Option[Configuration]): Def.Initialize[Task[ScalaInstance]] =
     Def.taskDyn {
       val sh = Keys.scalaHome.value
       val app = Keys.appConfiguration.value
@@ -35,7 +43,7 @@ private[sbt] object Compiler {
           val scalaProvider = app.provider.scalaProvider
           if (!managed) emptyScalaInstance
           else if (sv == scalaProvider.version) optimizedScalaInstance(sv, scalaProvider)
-          else scalaInstanceFromUpdate
+          else scalaInstanceFromUpdate(extraToolConf)
       }
     }
 
@@ -95,60 +103,49 @@ private[sbt] object Compiler {
     )
   }
 
-  def scalaInstanceFromUpdate: Def.Initialize[Task[ScalaInstance]] = Def.task {
-    val sv = Keys.scalaVersion.value
-    val fullReport = Keys.update.value
-    val s = Keys.streams.value
+  /**
+   * Returns a ScalaInstance.
+   * extraToolConf is used for Scala 3 since it started splitting up scaladoc and repl.
+   */
+  def scalaInstanceFromUpdate(
+      extraToolConf: Option[Configuration]
+  ): Def.Initialize[Task[ScalaInstance]] =
+    Def.task {
+      val sv = Keys.scalaVersion.value
+      val fullReport = Keys.update.value
+      val s = Keys.streams.value
 
-    // For Scala 3, update scala-library.jar in `scala-tool` and `scala-doc-tool` in case a newer version
-    // is present in the `compile` configuration. This is needed once forwards binary compatibility is dropped
-    // to avoid NoSuchMethod exceptions when expanding macros.
-    def updateLibraryToCompileConfiguration(report: ConfigurationReport) =
-      if (!ScalaArtifacts.isScala3(sv)) report
-      else
-        (for {
-          compileConf <- fullReport.configuration(Configurations.Compile)
-          compileLibMod <- compileConf.modules.find(_.module.name == ScalaArtifacts.LibraryID)
-          reportLibMod <- report.modules.find(_.module.name == ScalaArtifacts.LibraryID)
-          if VersionNumber(reportLibMod.module.revision)
-            .matchesSemVer(SemanticSelector(s"<${compileLibMod.module.revision}"))
-        } yield {
-          val newMods = report.modules
-            .filterNot(_.module.name == ScalaArtifacts.LibraryID) :+ compileLibMod
-          report.withModules(newMods)
-        }).getOrElse(report)
+      val toolReport = updateLibraryToCompileConfiguration(sv, fullReport)(
+        fullReport
+          .configuration(Configurations.ScalaTool)
+          .getOrElse(sys.error(noToolConfiguration(Keys.managedScalaInstance.value)))
+      )
 
-    val toolReport = updateLibraryToCompileConfiguration(
-      fullReport
-        .configuration(Configurations.ScalaTool)
-        .getOrElse(sys.error(noToolConfiguration(Keys.managedScalaInstance.value)))
-    )
-
-    if (Classpaths.isScala213(sv)) {
-      val scalaDeps = for {
-        compileReport <- fullReport.configuration(Configurations.Compile).iterator
-        libName <- ScalaArtifacts.Artifacts.iterator
-        lib <- compileReport.modules.find(_.module.name == libName)
-      } yield lib
-      for (lib <- scalaDeps.take(1)) {
-        val libVer = lib.module.revision
-        val libName = lib.module.name
-        val proj =
-          Def.displayBuildRelative(Keys.thisProjectRef.value.build, Keys.thisProjectRef.value)
-        if (VersionNumber(sv).matchesSemVer(SemanticSelector(s"<$libVer"))) {
-          val err = !Keys.allowUnsafeScalaLibUpgrade.value
-          val fix =
-            if (err)
-              """Upgrade the `scalaVersion` to fix the build. If upgrading the Scala compiler version is
+      if (Classpaths.isScala213(sv)) {
+        val scalaDeps = for {
+          compileReport <- fullReport.configuration(Configurations.Compile).iterator
+          libName <- ScalaArtifacts.Artifacts.iterator
+          lib <- compileReport.modules.find(_.module.name == libName)
+        } yield lib
+        for (lib <- scalaDeps.take(1)) {
+          val libVer = lib.module.revision
+          val libName = lib.module.name
+          val proj =
+            Def.displayBuildRelative(Keys.thisProjectRef.value.build, Keys.thisProjectRef.value)
+          if (VersionNumber(sv).matchesSemVer(SemanticSelector(s"<$libVer"))) {
+            val err = !Keys.allowUnsafeScalaLibUpgrade.value
+            val fix =
+              if (err)
+                """Upgrade the `scalaVersion` to fix the build. If upgrading the Scala compiler version is
                 |not possible (for example due to a regression in the compiler or a missing dependency),
                 |this error can be demoted by setting `allowUnsafeScalaLibUpgrade := true`.""".stripMargin
-            else
-              s"""Note that the dependency classpath and the runtime classpath of your project
+              else
+                s"""Note that the dependency classpath and the runtime classpath of your project
                  |contain the newer $libName $libVer, even if the scalaVersion is $sv.
                  |Compilation (macro expansion) or using the Scala REPL in sbt may fail with a LinkageError.""".stripMargin
 
-          val msg =
-            s"""Expected `$proj scalaVersion` to be $libVer or later, but found $sv.
+            val msg =
+              s"""Expected `$proj scalaVersion` to be $libVer or later, but found $sv.
                |To support backwards-only binary compatibility (SIP-51), the Scala 2.13 compiler
                |should not be older than $libName on the dependency classpath.
                |
@@ -156,60 +153,84 @@ private[sbt] object Compiler {
                |
                |See `$proj evicted` to know why $libName $libVer is getting pulled in.
                |""".stripMargin
-          if (err) sys.error(msg)
-          else s.log.warn(msg)
+            if (err) sys.error(msg)
+            else s.log.warn(msg)
+          }
         }
       }
-    }
-    def file(id: String): File = {
-      val files = for {
-        m <- toolReport.modules if m.module.name.startsWith(id)
-        (art, file) <- m.artifacts if art.`type` == Artifact.DefaultType
-      } yield file
-      files.headOption getOrElse sys.error(s"Missing $id jar file")
+      def file(id: String): File = {
+        val files = for {
+          m <- toolReport.modules if m.module.name.startsWith(id)
+          (art, file) <- m.artifacts if art.`type` == Artifact.DefaultType
+        } yield file
+        files.headOption getOrElse sys.error(s"Missing $id jar file")
+      }
+
+      val allCompilerJars = toolReport.modules.flatMap(_.artifacts.map(_._2))
+      val extraToolJars =
+        extraToolConf match {
+          case Some(extra) =>
+            fullReport
+              .configuration(extra)
+              .map(updateLibraryToCompileConfiguration(sv, fullReport))
+              .toSeq
+              .flatMap(_.modules)
+              .flatMap(_.artifacts.map(_._2))
+          case None => Nil
+        }
+      val libraryJars = ScalaArtifacts.libraryIds(sv).map(file)
+
+      makeScalaInstance(
+        sv,
+        libraryJars,
+        allCompilerJars,
+        extraToolJars,
+        Keys.state.value,
+        Keys.scalaInstanceTopLoader.value,
+      )
     }
 
-    val allCompilerJars = toolReport.modules.flatMap(_.artifacts.map(_._2))
-    val allDocJars =
-      fullReport
-        .configuration(Configurations.ScalaDocTool)
-        .map(updateLibraryToCompileConfiguration)
-        .toSeq
-        .flatMap(_.modules)
-        .flatMap(_.artifacts.map(_._2))
-    val libraryJars = ScalaArtifacts.libraryIds(sv).map(file)
-
-    makeScalaInstance(
-      sv,
-      libraryJars,
-      allCompilerJars,
-      allDocJars,
-      Keys.state.value,
-      Keys.scalaInstanceTopLoader.value,
-    )
-  }
+  // For Scala 3, update scala-library.jar in `scala-tool` and `scala-doc-tool` in case a newer version
+  // is present in the `compile` configuration. This is needed once forwards binary compatibility is dropped
+  // to avoid NoSuchMethod exceptions when expanding macros.
+  private def updateLibraryToCompileConfiguration(sv: String, fullReport: UpdateReport)(
+      report: ConfigurationReport
+  ) =
+    if (!ScalaArtifacts.isScala3(sv)) report
+    else
+      (for {
+        compileConf <- fullReport.configuration(Configurations.Compile)
+        compileLibMod <- compileConf.modules.find(_.module.name == ScalaArtifacts.LibraryID)
+        reportLibMod <- report.modules.find(_.module.name == ScalaArtifacts.LibraryID)
+        if VersionNumber(reportLibMod.module.revision)
+          .matchesSemVer(SemanticSelector(s"<${compileLibMod.module.revision}"))
+      } yield {
+        val newMods = report.modules
+          .filterNot(_.module.name == ScalaArtifacts.LibraryID) :+ compileLibMod
+        report.withModules(newMods)
+      }).getOrElse(report)
 
   def makeScalaInstance(
       version: String,
       libraryJars: Array[File],
       allCompilerJars: Seq[File],
-      allDocJars: Seq[File],
+      extraToolJars: Seq[File],
       state: State,
       topLoader: ClassLoader,
   ): ScalaInstance = {
     val classLoaderCache = state.extendedClassLoaderCache
     val compilerJars = allCompilerJars.filterNot(libraryJars.contains).distinct.toArray
-    val docJars = allDocJars
+    val toolJars = extraToolJars
       .filterNot(jar => libraryJars.contains(jar) || compilerJars.contains(jar))
       .distinct
       .toArray
-    val allJars = libraryJars ++ compilerJars ++ docJars
+    val allJars = libraryJars ++ compilerJars ++ toolJars
 
     val libraryLoader = classLoaderCache(libraryJars.toList, topLoader)
     val compilerLoader = classLoaderCache(compilerJars.toList, libraryLoader)
     val fullLoader =
-      if (docJars.isEmpty) compilerLoader
-      else classLoaderCache(docJars.distinct.toList, compilerLoader)
+      if (toolJars.isEmpty) compilerLoader
+      else classLoaderCache(toolJars.distinct.toList, compilerLoader)
     new ScalaInstance(
       version = version,
       loader = fullLoader,
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index c14030431..47d798632 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -14,8 +14,8 @@ object Dependencies {
   // sbt modules
   private val ioVersion = nightlyVersion.getOrElse("1.10.5")
   private val lmVersion =
-    sys.props.get("sbt.build.lm.version").orElse(nightlyVersion).getOrElse("1.11.6")
-  val zincVersion = nightlyVersion.getOrElse("1.11.0")
+    sys.props.get("sbt.build.lm.version").orElse(nightlyVersion).getOrElse("1.12.0-M1")
+  val zincVersion = nightlyVersion.getOrElse("1.12.0-M1")
 
   private val sbtIO = "org.scala-sbt" %% "io" % ioVersion
 

From 854d76b761a013a356bda3b3e14b2481046d5212 Mon Sep 17 00:00:00 2001
From: eugene yokota <eed3si9n@gmail.com>
Date: Mon, 3 Nov 2025 14:11:11 -0500
Subject: [PATCH 14/17] Update checkout references to 1.12.x

---
 .github/workflows/ci.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a3f264a16..0a5682d4c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -59,13 +59,13 @@ jobs:
       uses: actions/checkout@v5
       with:
         repository: sbt/librarymanagement
-        ref: develop
+        ref: 1.12.x
         path: librarymanagement
     - name: Checkout sbt/zinc
       uses: actions/checkout@v5
       with:
         repository: sbt/zinc
-        ref: 1.10.x
+        ref: 1.12.x
         path: zinc
     - name: Setup JDK
       uses: actions/setup-java@v5

From ce117c5584be03c10fd97db9226862098b209e67 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Mon, 3 Nov 2025 19:53:22 +0000
Subject: [PATCH 15/17] [1.x] Bump coursier/cache-action from 6 to 7

Bumps [coursier/cache-action](https://github.com/coursier/cache-action) from 6 to 7.
- [Release notes](https://github.com/coursier/cache-action/releases)
- [Commits](https://github.com/coursier/cache-action/compare/v6...v7)

---
updated-dependencies:
- dependency-name: coursier/cache-action
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
---
 .github/workflows/nightly.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index a4aa1fd19..3f601beab 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -46,7 +46,7 @@ jobs:
         distribution: "${{ matrix.distribution }}"
         java-version: "${{ matrix.java }}"
     - name: Coursier cache
-      uses: coursier/cache-action@v6
+      uses: coursier/cache-action@v7
     - name: Build and deploy
       run: |
         # build from fresh IO, LM, and Zinc

From 6daa99b2dbba2e75ca16738de8f3d60d974f2aca Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Fri, 14 Nov 2025 00:38:03 -0500
Subject: [PATCH 16/17] fix: Parse with -Xsource:3

**Problem**
On IntelliJ the users are getting the hint to upgrade to -Xsource:3
style, however the supported syntax do not parse.

**Solution**
This adds -Xsource:3 to the parser. The metabuild compilation uses
-Xsource:3 since sbt 1.6.0.
---
 .../scala/sbt/internal/parser/SbtParser.scala |  2 +-
 main/src/test/resources/xsource3/1.sbt.txt    |  7 ++++
 .../sbt/internal/parser/Xsource3Spec.scala    | 33 +++++++++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 main/src/test/resources/xsource3/1.sbt.txt
 create mode 100644 main/src/test/scala/sbt/internal/parser/Xsource3Spec.scala

diff --git a/main/src/main/scala/sbt/internal/parser/SbtParser.scala b/main/src/main/scala/sbt/internal/parser/SbtParser.scala
index eb7bed7cb..f703cf271 100644
--- a/main/src/main/scala/sbt/internal/parser/SbtParser.scala
+++ b/main/src/main/scala/sbt/internal/parser/SbtParser.scala
@@ -129,7 +129,7 @@ private[sbt] object SbtParser {
   private[sbt] var scalacGlobalInitReporter: Option[ConsoleReporter] = None
 
   private[sbt] final val (defaultGlobalForParser, globalReporter) = {
-    val options = "-cp" :: s"$defaultClasspath" :: "-Yrangepos" :: Nil
+    val options = "-cp" :: s"$defaultClasspath" :: "-Yrangepos" :: "-Xsource:3" :: Nil
     val reportError = (msg: String) => System.err.println(msg)
     val command = new CompilerCommand(options, reportError)
     val settings = command.settings
diff --git a/main/src/test/resources/xsource3/1.sbt.txt b/main/src/test/resources/xsource3/1.sbt.txt
new file mode 100644
index 000000000..d37ff7c3a
--- /dev/null
+++ b/main/src/test/resources/xsource3/1.sbt.txt
@@ -0,0 +1,7 @@
+ThisBuild / scalaVersion := "3.3.4"
+
+def foo(): Unit = {
+  List("") match { case List(path@_*) => () }
+  List("") match { case List(path *) => () }
+  List("") match { case List(path*) => () }
+}
diff --git a/main/src/test/scala/sbt/internal/parser/Xsource3Spec.scala b/main/src/test/scala/sbt/internal/parser/Xsource3Spec.scala
new file mode 100644
index 000000000..1c1b9a658
--- /dev/null
+++ b/main/src/test/scala/sbt/internal/parser/Xsource3Spec.scala
@@ -0,0 +1,33 @@
+/*
+ * sbt
+ * Copyright 2023, Scala center
+ * Copyright 2011 - 2022, Lightbend, Inc.
+ * Copyright 2008 - 2010, Mark Harrah
+ * Licensed under Apache License 2.0 (see LICENSE)
+ */
+
+package sbt
+package internal
+package parser
+
+import java.io.File
+
+import scala.io.Source
+
+object Xsource3Spec extends AbstractSpec {
+  implicit val splitter: SplitExpressions.SplitExpression = EvaluateConfigurations.splitExpressions
+
+  test("Parser should handle -Xsource:3 syntax") {
+    val rootPath = getClass.getResource("/xsource3").getPath
+    println(s"Reading files from: $rootPath")
+    val allFiles = new File(rootPath).listFiles.toList
+    allFiles foreach { path =>
+      println(s"$path")
+      val lines = Source.fromFile(path).getLines().toList
+      val (_, statements) = splitter(path, lines)
+      assert(statements.nonEmpty, s"""
+           |***should contains statements***
+           |$lines """.stripMargin)
+    }
+  }
+}

From ee03e7606ee43f9269400a4267a0f0467f613f8a Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Mon, 24 Nov 2025 04:43:00 +0000
Subject: [PATCH 17/17] [1.x] Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
---
 .github/workflows/ci.yml               | 8 ++++----
 .github/workflows/client-test.yml      | 2 +-
 .github/workflows/dependency-graph.yml | 2 +-
 .github/workflows/nightly.yml          | 8 ++++----
 .github/workflows/server-test.yml      | 2 +-
 5 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0a5682d4c..3c3e3d839 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -48,21 +48,21 @@ jobs:
       SPARK_LOCAL_IP: "127.0.0.1"
     steps:
     - name: Checkout sbt/sbt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Checkout sbt/io
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/io
         ref: develop
         path: io
     - name: Checkout sbt/librarymanagement
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/librarymanagement
         ref: 1.12.x
         path: librarymanagement
     - name: Checkout sbt/zinc
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/zinc
         ref: 1.12.x
diff --git a/.github/workflows/client-test.yml b/.github/workflows/client-test.yml
index df0ef6ab4..4b7c51903 100644
--- a/.github/workflows/client-test.yml
+++ b/.github/workflows/client-test.yml
@@ -28,7 +28,7 @@ jobs:
       SBT_ETC_FILE: $HOME/etc/sbt/sbtopts
       TEST_SBT_VER: 1.11.4
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Setup JDK
       uses: actions/setup-java@v5
       with:
diff --git a/.github/workflows/dependency-graph.yml b/.github/workflows/dependency-graph.yml
index cbad57297..5414f60eb 100644
--- a/.github/workflows/dependency-graph.yml
+++ b/.github/workflows/dependency-graph.yml
@@ -12,6 +12,6 @@ jobs:
     name: Submit Dependency Graph
     runs-on: ubuntu-latest # or windows-latest, or macOS-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: sbt/setup-sbt@v1
       - uses: scalacenter/sbt-dependency-submission@v3
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 3f601beab..9bfeef14d 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -21,21 +21,21 @@ jobs:
       JAVA_OPTS: -Xms800M -Xmx800M -Xss6M -XX:ReservedCodeCacheSize=128M -server -Dsbt.io.virtual=false -Dfile.encoding=UTF-8
     steps:
     - name: Checkout sbt/sbt
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Checkout sbt/io
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/io
         ref: develop
         path: io
     - name: Checkout sbt/librarymanagement
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/librarymanagement
         ref: develop
         path: librarymanagement
     - name: Checkout sbt/zinc
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: sbt/zinc
         ref: 1.10.x
diff --git a/.github/workflows/server-test.yml b/.github/workflows/server-test.yml
index f5a0902c8..07871cb31 100644
--- a/.github/workflows/server-test.yml
+++ b/.github/workflows/server-test.yml
@@ -14,7 +14,7 @@ jobs:
       JVM_OPTS: -Xms800M -Xmx2G -Xss6M -XX:ReservedCodeCacheSize=128M -server -Dsbt.io.virtual=false -Dfile.encoding=UTF-8
       SBT_ETC_FILE: $HOME/etc/sbt/sbtopts
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Setup JDK
       uses: actions/setup-java@v5
       with: