Try another travis structure + build tweaks

I've tried to put together some scripted tests to remove the overhead of
compiling the whole sbt, which is around 3 minutes every time.

This new structure *should* make the scripted tests run faster.

Aside from this, we do some more tweaks:

* Increase memory.
* Fork processes to compile and run (to see if it makes a difference).
* Pass in the server flag to sbt.

.travis.yml

@@ -16,29 +16,17 @@ matrix:
 
 env:
   matrix:
-    - SBT_CMD=";test:compile;scalafmtCheck"
-    - SBT_CMD="mimaReportBinaryIssues"
-    - SBT_CMD="safeUnitTests"
-    - SBT_CMD="otherUnitTests"
+    - SBT_CMD=";mimaReportBinaryIssues;test:compile;scalafmtCheck;safeUnitTests;otherUnitTests"
     - SBT_CMD="scripted actions/*"
-    - SBT_CMD="scripted apiinfo/*"
-    - SBT_CMD="scripted compiler-project/*"
+    - SBT_CMD="scripted apiinfo/* compiler-project/* ivy-deps-management/*"
     - SBT_CMD="scripted dependency-management/*1of4"
     - SBT_CMD="scripted dependency-management/*2of4"
     - SBT_CMD="scripted dependency-management/*3of4"
     - SBT_CMD="scripted dependency-management/*4of4"
-    - SBT_CMD="scripted ivy-deps-management/*"
-    - SBT_CMD="scripted java/*"
-    - SBT_CMD="scripted package/*"
-    - SBT_CMD="scripted project/*1of2"
-    - SBT_CMD="scripted project/*2of2"
-    - SBT_CMD="scripted reporter/*"
-    - SBT_CMD="scripted run/*"
-    - SBT_CMD="scripted source-dependencies/*1of3"
-    - SBT_CMD="scripted source-dependencies/*2of3"
-    - SBT_CMD="scripted source-dependencies/*3of3"
+    - SBT_CMD="scripted java/* package/* reporter/* run/*"
+    - SBT_CMD="scripted project/* project-load/*"
+    - SBT_CMD="scripted source-dependencies/*"
     - SBT_CMD="scripted tests/*"
-    - SBT_CMD="scripted project-load/*"
     - SBT_CMD="repoOverrideTest:scripted dependency-management/*"
 
 notifications:
@@ -46,7 +34,8 @@ notifications:
     - sbt-dev-bot@googlegroups.com
 
 script:
-  - sbt -J-XX:ReservedCodeCacheSize=128m -J-Xmx1g -J-Xms1g "$SBT_CMD"
+  # It doesn't need that much memory because compile and run are forked
+  - sbt -J-XX:ReservedCodeCacheSize=128m -J-Xmx800M -J-Xms800M -J-server "$SBT_CMD"
 
 before_cache:
   - find $HOME/.ivy2 -name "ivydata-*.properties" -print -delete

build.sbt

@@ -53,7 +53,9 @@ def commonSettings: Seq[Setting[_]] =
     mimaBinaryIssueFilters ++= {
       import com.typesafe.tools.mima.core._, ProblemFilters._
       Seq()
-    }
+    },
+    fork in compile := true,
+    fork in run := true
   ) flatMap (_.settings)
 
 def minimalSettings: Seq[Setting[_]] =
@@ -352,7 +354,7 @@ def otherRootSettings =
     scriptedUnpublished := scriptedUnpublishedTask.evaluated,
     scriptedSource := (sourceDirectory in sbtProj).value / "sbt-test",
     // scriptedPrescripted := { addSbtAlternateResolver _ },
-    scriptedLaunchOpts := List("-Xmx1024M", "-Xms512M"),
+    scriptedLaunchOpts := List("-Xmx1500M", "-Xms512M", "-server"),
     publishAll := { val _ = (publishLocal).all(ScopeFilter(inAnyProject)).value },
     publishLocalBinAll := { val _ = (publishLocalBin).all(ScopeFilter(inAnyProject)).value },
     aggregate in bintrayRelease := false
@@ -362,8 +364,9 @@ def otherRootSettings =
         ()
       },
       scriptedLaunchOpts := {
-        List("-Xmx1024M",
+        List("-Xmx1500M",
              "-Xms512M",
+             "-server",
              "-Dsbt.override.build.repos=true",
              s"""-Dsbt.repository.config=${scriptedSource.value / "repo.config"}""")
       },

scripted/sbt/src/main/scala/sbt/test/ScriptedTests.scala

@@ -111,7 +111,7 @@ final class ScriptedTests(resourceBaseDirectory: File,
    *
    * It sets the name of the local root project for those tests run in batch mode.
    *
-   * This is necessary because the current design to run tests in batch mode force
+   * This is necessary because the current design to run tests in batch mode forces
    * scripted tests to share one common sbt dir instead of each one having its own.
    *
    * Sbt extracts the local root project name from the directory name. So those
@@ -184,14 +184,22 @@ final class ScriptedTests(resourceBaseDirectory: File,
             // Reload and initialize (to reload contents of .sbtrc files)
             val pluginImplementation = createAutoPlugin(name)
             IO.write(tempTestDir / "project" / "InstrumentScripted.scala", pluginImplementation)
-            val sbtHandler = handlers.getOrElse('>', sys.error("Missing sbt handler."))
+            val sbtHandlerError = "Missing sbt handler. Scripted is misconfigured."
+            val sbtHandler = handlers.getOrElse('>', sbtHandlerError).asInstanceOf[SbtHandler]
             val commandsToRun = ";reload;setUpScripted"
             val statement = Statement(commandsToRun, Nil, successExpected = true, line = -1)
+
             // Run reload inside the hook to reuse error handling for pending tests
             val wrapHook = (file: File) => {
               preHook(file)
-              runner.processStatement(sbtHandler.asInstanceOf[SbtHandler], statement, states)
+              try runner.processStatement(sbtHandler, statement, states)
+              catch {
+                case t: Throwable =>
+                  val newMsg = "Reload for scripted batch execution failed."
+                  throw new TestException(statement, newMsg, t)
+              }
             }
+
             commonRunTest(label, tempTestDir, wrapHook, handlers, runner, states, buffer)
           }