Preserve caches between interactive and client/server mode (#342)

We were incorrectly duplicating the JDK classpath as part of the application classpath when we spawned the Mill server from the Mill client. This makes the transmission of application classpath to the Mill server explicit via an environment variable, so we don't end up including random things from the client classloader hierarchy that we didn't expect

4 files changed, 9 insertions, 16 deletions

diff --git a/build.sc b/build.sc
index 7f0f6e10..f5b61d4c 100755
--- a/build.sc
+++ b/build.sc
@@ -316,7 +316,10 @@ object dev extends MillModule{
     val classpath = runClasspath().map(_.path.toString)
     val args = forkArgs().distinct
     val (shellArgs, cmdArgs) =
-      if (!scala.util.Properties.isWin) (args, args)
+      if (!scala.util.Properties.isWin) (
+        Seq("-DMILL_CLASSPATH=" + classpath.mkString(":")) ++ args,
+        Seq("-DMILL_CLASSPATH=" + classpath.mkString(";")) ++ args
+      )
       else (
         Seq("""-XX:VMOptionsFile="$( dirname "$0" )"/mill.vmoptions"""),
         Seq("""-XX:VMOptionsFile=%~dp0\mill.vmoptions""")
@@ -345,6 +348,7 @@ def release = T{
   val dest = T.ctx().dest
   val filename = if (scala.util.Properties.isWin) "mill.bat" else "mill"
   val args = Seq(
+    "-DMILL_CLASSPATH=$0",
     "-DMILL_VERSION=" + publishVersion()._2,
     // Workaround for Zinc/JNA bug
     // https://github.com/sbt/sbt/blame/6718803ee6023ab041b045a6988fafcfae9d15b5/main/src/main/scala/sbt/Main.scala#L130
diff --git a/main/client/src/mill/main/client/MillClientMain.java b/main/client/src/mill/main/client/MillClientMain.java
index 17a043f6..e3d3ec6e 100644
--- a/main/client/src/mill/main/client/MillClientMain.java
+++ b/main/client/src/mill/main/client/MillClientMain.java
@@ -11,20 +11,8 @@ import java.util.*;
 
 public class MillClientMain {
     static void initServer(String lockBase, boolean setJnaNoSys) throws IOException,URISyntaxException{
-        ArrayList<String> selfJars = new ArrayList<String>();
-        ClassLoader current = MillClientMain.class.getClassLoader();
-        while(current != null){
-            if (current instanceof java.net.URLClassLoader) {
-                URL[] urls = ((java.net.URLClassLoader) current).getURLs();
-                for (URL url: urls) {
-                    selfJars.add(new File(url.toURI()).getCanonicalPath());
-                }
-            }
-            current = current.getParent();
-        }
-        if (Util.isJava9OrAbove) {
-            selfJars.addAll(Arrays.asList(System.getProperty("java.class.path").split(File.pathSeparator)));
-        }
+        String[] selfJars = System.getProperty("MILL_CLASSPATH").split(File.pathSeparator);
+
         ArrayList<String> l = new java.util.ArrayList<String>();
         l.add("java");
         Properties props = System.getProperties();
diff --git a/main/src/mill/main/RunScript.scala b/main/src/mill/main/RunScript.scala
index 50cbb213..5f10db44 100644
--- a/main/src/mill/main/RunScript.scala
+++ b/main/src/mill/main/RunScript.scala
@@ -76,6 +76,7 @@ object RunScript{
                          log: Logger
                         ): Res[mill.define.BaseModule] = {
 
+    log.info("RunScript.evaluateRootModule")
     val (pkg, wrapper) = Util.pathToPackageWrapper(Seq(), path relativeTo wd)
 
     for {
diff --git a/scratch/build.sc b/scratch/build.sc
index 9ee78d63..ae763e4d 100644
--- a/scratch/build.sc
+++ b/scratch/build.sc
@@ -1,3 +1,3 @@
 def thingy = T {
-  1234567
+  12345678
 }
\ No newline at end of file