Fix MILL_CLASSPATH for Windows (#354)

* Use comma as separator in MILL_CLASSPATH

There is no need to use environment-specific separator, especially since

 - other variables are using commas anyway, and
 - it is not sent to any system-level command

* Fix whitespace

* Use MILL_CLASSPATH for Windows

* Use vm options file for client on windows

* Remove overzealous distinct

* Clean up unnecessary ceremony

1 files changed, 15 insertions, 9 deletions

diff --git a/build.sc b/build.sc
index ef7fdf9d..f018b8a1 100755
--- a/build.sc
+++ b/build.sc
@@ -294,12 +294,18 @@ def launcherScript(shellJvmArgs: Seq[String],
 object dev extends MillModule{
   def moduleDeps = Seq(scalalib, scalajslib)
   def forkArgs =
-    (scalalib.testArgs() ++
-     scalajslib.testArgs() ++
-     scalalib.worker.testArgs() ++
-     // Workaround for Zinc/JNA bug
-     // https://github.com/sbt/sbt/blame/6718803ee6023ab041b045a6988fafcfae9d15b5/main/src/main/scala/sbt/Main.scala#L130
-     Seq("-Djna.nosys=true", "-DMILL_VERSION=" + build.publishVersion()._2)).distinct
+    (
+      scalalib.testArgs() ++
+      scalajslib.testArgs() ++
+      scalalib.worker.testArgs() ++
+      // Workaround for Zinc/JNA bug
+      // https://github.com/sbt/sbt/blame/6718803ee6023ab041b045a6988fafcfae9d15b5/main/src/main/scala/sbt/Main.scala#L130
+      Seq(
+        "-Djna.nosys=true",
+        "-DMILL_VERSION=" + build.publishVersion()._2,
+        "-DMILL_CLASSPATH=" + runClasspath().map(_.path.toString).mkString(",")
+      )
+    ).distinct
 
   // Pass dev.assembly VM options via file in Window due to small max args limit
   def windowsVmOptions(taskName: String, batch: Path, args: Seq[String])(implicit ctx: mill.util.Ctx) = {
@@ -339,11 +345,11 @@ object dev extends MillModule{
 
   def prependShellScript = T{
     val classpath = runClasspath().map(_.path.toString)
-    val args = forkArgs().distinct
+    val args = forkArgs()
     val (shellArgs, cmdArgs) =
       if (!scala.util.Properties.isWin) (
-        Seq("-DMILL_CLASSPATH=" + classpath.mkString(":")) ++ args,
-        Seq("-DMILL_CLASSPATH=" + classpath.mkString(";")) ++ args
+        args,
+        args
       )
       else (
         Seq("""-XX:VMOptionsFile="$( dirname "$0" )"/mill.vmoptions"""),