bump to sbt 1.5.0-RC2

Author: adpi2

.github/workflows/ci.yaml

@@ -322,12 +322,9 @@ jobs:
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
 
-      - name: Test sbt 1.4.x
+      - name: Test sbt
         run: ./project/scripts/sbt "sbt-dotty/scripted; sbt-community-build/scripted"
 
-      - name: Test sbt 1.5.x
-        run: ./project/scripts/sbt "set \`sbt-dotty\`/scriptedSbt := \"1.5.0-RC1\"; sbt-dotty/scripted sbt-dotty/*"
-
   test_java8:
     runs-on: [self-hosted, Linux]
     container:

community-build/src/scala/dotty/communitybuild/projects.scala

@@ -121,7 +121,7 @@ final case class SbtCommunityProject(
       case Some(ivyHome) => List(s"-Dsbt.ivy.home=$ivyHome")
       case _ => Nil
     extraSbtArgs ++ sbtProps ++ List(
-      "-sbt-version", "1.4.9",
+      "-sbt-version", "1.5.0-RC2",
       "-Dsbt.supershell=false",
       s"-Ddotty.communitybuild.dir=$communitybuildDir",
       s"--addPluginSbtFile=$sbtPluginFilePath"

project/Build.scala

@@ -1202,6 +1202,9 @@ object Build {
         baseDirectory.value / "../language-server/src/dotty/tools/languageserver/config",
       sbtTestDirectory := baseDirectory.value / "sbt-test",
 
+      // ensure that sbt-dotty is built on sbt 1.4
+      pluginCrossBuild / sbtVersion := "1.4.9",
+
       // The batch mode accidentally became the default with no way to disable
       // it in sbt 1.4 (https://github.com/sbt/sbt/issues/5913#issuecomment-716003195).
       // We enable it explicitly here to make it clear that we're using it.

project/build.properties

@@ -1 +1 @@
-sbt.version=1.4.9
+sbt.version=1.5.0-RC2