Make sbt scripted tests use the right ivy HOME

When running the CI, ivy HOME is not the default one but sbt scripted
tests used to use the default one anyway

Author: allanrenucci

project/Build.scala

@@ -877,6 +877,8 @@ object Build {
       ScriptedPlugin.scriptedBufferLog := false,
       ScriptedPlugin.scriptedLaunchOpts += "-Dplugin.version=" + version.value,
       ScriptedPlugin.scriptedLaunchOpts += "-Dplugin.scalaVersion=" + dottyVersion,
+     // By default scripted tests use $HOME/.ivy2 for the ivy cache. We need to override this value for the CI.
+      ScriptedPlugin.scriptedLaunchOpts ++= ivyPaths.value.ivyHome.map("-Dsbt.ivy.home=" + _.getAbsolutePath).toList,
       ScriptedPlugin.scripted := ScriptedPlugin.scripted.dependsOn(Def.task {
         val x0 = (publishLocal in `dotty-sbt-bridge-bootstrapped`).value
         val x1 = (publishLocal in `dotty-interfaces`).value

project/scripts/sbt

@@ -10,12 +10,10 @@ if [ -z "$CMD" ]; then
   exit 1
 fi
 
-# get the ivy2 cache
-ln -s /var/cache/drone/ivy2 "$HOME/.ivy2"
-
 # run sbt with the supplied arg
 sbt -J-Xmx4096m \
     -J-XX:ReservedCodeCacheSize=512m \
     -J-XX:MaxMetaspaceSize=1024m \
     -Ddotty.drone.mem=4096m \
+    -Dsbt.ivy.home=/var/cache/drone/ivy2 \
     "$CMD"