diff --git a/cbt b/cbt
index 1ec2d0f0..f74cbbd5 100755
--- a/cbt
+++ b/cbt
@@ -141,7 +141,12 @@ if [ ! "$DEBUG" == "" ]; then
 	shift
 fi
 
-JAVA_OPTS_CBT=($DEBUG -Xmx1536m -Xss10M "-XX:MaxJavaStackTraceDepth=-1" -XX:+TieredCompilation "-XX:TieredStopAtLevel=1" -Xverify:none)
+# shellcheck disable=SC2153
+if [ -z "${JAVA_OPTS_CBT+x}" ]; then
+	_JAVA_OPTS_CBT=($DEBUG -Xmx1536m -Xss10M "-XX:MaxJavaStackTraceDepth=-1" -XX:+TieredCompilation "-XX:TieredStopAtLevel=1" -Xverify:none)
+else
+	_JAVA_OPTS_CBT=($DEBUG $JAVA_OPTS_CBT)
+fi
 
 # ng on osx, install via brew install nailgun
 # ng-nailgun on unbuntu, install via apt-get install nailgun
@@ -214,7 +219,7 @@ fi
 if [ $use_nailgun -eq 0 ] && [ ! $server_up -eq 0 ]; then
 	log "Starting background process (nailgun)" "$@"
 	# try to start nailgun-server, just in case it's not up
-	java "${options[@]}" "${JAVA_OPTS_CBT[@]}" -jar "$NG_SERVER_JAR" 127.0.0.1:$NAILGUN_PORT >> "$nailgun_out" 2>> "$nailgun_err" &
+	java "${_JAVA_OPTS_CBT[@]}" -jar "$NG_SERVER_JAR" 127.0.0.1:$NAILGUN_PORT >> "$nailgun_out" 2>> "$nailgun_err" &
 	if [ ! "$DEBUG" == "" ]; then
 		echo "Started nailgun server in debug mode"
 		exit 1
@@ -243,7 +248,7 @@ stage1 () {
 			touch -t "$COMPILE_TIME" "$NAILGUN_INDICATOR"
 			if [ $use_nailgun -eq 0 ]; then
 				echo "Starting background process (nailgun)" 1>&2
-				java "${options[@]}" "${JAVA_OPTS_CBT[@]}" -jar "$NG_SERVER_JAR" 127.0.0.1:$NAILGUN_PORT >> "$nailgun_out" 2>> "$nailgun_err" &
+				java "${_JAVA_OPTS_CBT[@]}" -jar "$NG_SERVER_JAR" 127.0.0.1:$NAILGUN_PORT >> "$nailgun_out" 2>> "$nailgun_err" &
 				sleep 1
 			fi
 		fi
@@ -255,9 +260,8 @@ stage1 () {
 		if [ ! $use_nailgun -eq 0 ]
 		then
 			log "Running JVM directly" "$@"
-			options=($JAVA_OPTS)
 			# JVM options to improve startup time. See https://github.com/cvogt/cbt/pull/262
-			java "${options[@]}" "${JAVA_OPTS_CBT[@]}" -cp "$NAILGUN$TARGET" cbt.NailgunLauncher "$(time_taken)" "$CWD" "$loop" "$@"
+			java "${_JAVA_OPTS_CBT[@]}" -cp "$NAILGUN$TARGET" cbt.NailgunLauncher "$(time_taken)" "$CWD" "$loop" "$@"
 			exitCode=$?
 		else
 			log "Running via background process (nailgun)" "$@"
diff --git a/compatibility/build/build.scala b/compatibility/build/build.scala
new file mode 100644
index 00000000..22fc0d66
--- /dev/null
+++ b/compatibility/build/build.scala
@@ -0,0 +1,6 @@
+package cbt_build.compatibility
+import cbt._
+class Build(val context: Context) extends BaseBuild{
+  // don't depend on Scala, not needed
+  override def dependencies = Seq()
+}
diff --git a/nailgun_launcher/EarlyDependencies.java b/nailgun_launcher/EarlyDependencies.java
index 5725e3ab..4cad5a10 100644
--- a/nailgun_launcher/EarlyDependencies.java
+++ b/nailgun_launcher/EarlyDependencies.java
@@ -10,9 +10,9 @@
 
 public class EarlyDependencies{
 
-  public static String scalaVersion = "2.11.8";
+  public static String scalaVersion = "2.11.11";
   public static String scalaXmlVersion = "1.0.6";
-  public static String zincVersion = "0.3.13";
+  public static String zincVersion = "0.3.15";
 
   /** ClassLoader for stage1 */
   ClassLoader classLoader;
@@ -29,20 +29,20 @@ public class EarlyDependencies{
   public EarlyDependencies(
     String mavenCache, String mavenUrl, ClassLoaderCache classLoaderCache, ClassLoader rootClassLoader
   ) throws Throwable {
-    String scalaReflect_2_11_8_File = mavenCache + "/org/scala-lang/scala-reflect/2.11.8/scala-reflect-2.11.8.jar";
-    String scalaCompiler_2_11_8_File = mavenCache + "/org/scala-lang/scala-compiler/2.11.8/scala-compiler-2.11.8.jar";
+    String scalaReflect_2_11_11_File = mavenCache + "/org/scala-lang/scala-reflect/2.11.11/scala-reflect-2.11.11.jar";
+    String scalaCompiler_2_11_11_File = mavenCache + "/org/scala-lang/scala-compiler/2.11.11/scala-compiler-2.11.11.jar";
     String scalaXml_1_0_6_File = mavenCache + "/org/scala-lang/modules/scala-xml_2.11/1.0.6/scala-xml_2.11-1.0.6.jar";
-    String scalaLibrary_2_11_8_File = mavenCache + "/org/scala-lang/scala-library/2.11.8/scala-library-2.11.8.jar";
-    String zinc_0_3_13_File = mavenCache + "/com/typesafe/zinc/zinc/0.3.13/zinc-0.3.13.jar";
-    String incrementalCompiler_0_13_13_File = mavenCache + "/com/typesafe/sbt/incremental-compiler/0.13.13/incremental-compiler-0.13.13.jar";
-    String compilerInterface_0_13_13_File = mavenCache + "/com/typesafe/sbt/compiler-interface/0.13.13/compiler-interface-0.13.13-sources.jar";
+    String scalaLibrary_2_11_11_File = mavenCache + "/org/scala-lang/scala-library/2.11.11/scala-library-2.11.11.jar";
+    String zinc_0_3_15_File = mavenCache + "/com/typesafe/zinc/zinc/0.3.15/zinc-0.3.15.jar";
+    String incrementalCompiler_0_13_15_File = mavenCache + "/com/typesafe/sbt/incremental-compiler/0.13.15/incremental-compiler-0.13.15.jar";
+    String compilerInterface_0_13_15_File = mavenCache + "/com/typesafe/sbt/compiler-interface/0.13.15/compiler-interface-0.13.15-sources.jar";
     String scalaCompiler_2_10_6_File = mavenCache + "/org/scala-lang/scala-compiler/2.10.6/scala-compiler-2.10.6.jar";
-    String sbtInterface_0_13_13_File = mavenCache + "/com/typesafe/sbt/sbt-interface/0.13.13/sbt-interface-0.13.13.jar";
+    String sbtInterface_0_13_15_File = mavenCache + "/com/typesafe/sbt/sbt-interface/0.13.15/sbt-interface-0.13.15.jar";
     String scalaReflect_2_10_6_File = mavenCache + "/org/scala-lang/scala-reflect/2.10.6/scala-reflect-2.10.6.jar";
     String scalaLibrary_2_10_6_File = mavenCache + "/org/scala-lang/scala-library/2.10.6/scala-library-2.10.6.jar";
 
-    download(new URL(mavenUrl + "/org/scala-lang/scala-reflect/2.11.8/scala-reflect-2.11.8.jar"), Paths.get(scalaReflect_2_11_8_File), "b74530deeba742ab4f3134de0c2da0edc49ca361");
-    download(new URL(mavenUrl + "/org/scala-lang/scala-compiler/2.11.8/scala-compiler-2.11.8.jar"), Paths.get(scalaCompiler_2_11_8_File), "fe1285c9f7b58954c5ef6d80b59063569c065e9a");
+    download(new URL(mavenUrl + "/org/scala-lang/scala-reflect/2.11.11/scala-reflect-2.11.11.jar"), Paths.get(scalaReflect_2_11_11_File), "2addc7e09cf2e77e2243a5772bd0430c32c2b410");
+    download(new URL(mavenUrl + "/org/scala-lang/scala-compiler/2.11.11/scala-compiler-2.11.11.jar"), Paths.get(scalaCompiler_2_11_11_File), "2f1568549280da6d0a332846cb7c27edae76fd10");
 
     // org.scala-lang:scala-library:2.10.6
     String[] scalaLibrary_2_10_6_ClasspathArray = new String[]{scalaLibrary_2_10_6_File};
@@ -66,92 +66,92 @@ public EarlyDependencies(
       scalaReflect_2_10_6_ClasspathArray
     );
 
-    // com.typesafe.sbt:sbt-interface:0.13.13
-    String[] sbtInterface_0_13_13_ClasspathArray = new String[]{sbtInterface_0_13_13_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    ClassLoader sbtInterface_0_13_13_ = loadDependency(
-      mavenUrl + "/com/typesafe/sbt/sbt-interface/0.13.13/sbt-interface-0.13.13.jar",
-      sbtInterface_0_13_13_File,
-      "9367c5c7a835f9505774fc3b7c3a8146a1396f85",
+    // com.typesafe.sbt:sbt-interface:0.13.15
+    String[] sbtInterface_0_13_15_ClasspathArray = new String[]{sbtInterface_0_13_15_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
+    ClassLoader sbtInterface_0_13_15_ = loadDependency(
+      mavenUrl + "/com/typesafe/sbt/sbt-interface/0.13.15/sbt-interface-0.13.15.jar",
+      sbtInterface_0_13_15_File,
+      "93fe450d5f5efb111397a34bc1fba0d50368a265",
       classLoaderCache,
       scalaReflect_2_10_6_,
-      sbtInterface_0_13_13_ClasspathArray
+      sbtInterface_0_13_15_ClasspathArray
     );
 
     // org.scala-lang:scala-compiler:2.10.6
-    String[] scalaCompiler_2_10_6_ClasspathArray = new String[]{sbtInterface_0_13_13_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
+    String[] scalaCompiler_2_10_6_ClasspathArray = new String[]{sbtInterface_0_13_15_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
     ClassLoader scalaCompiler_2_10_6_ = loadDependency(
       mavenUrl + "/org/scala-lang/scala-compiler/2.10.6/scala-compiler-2.10.6.jar",
       scalaCompiler_2_10_6_File,
       "9b15174852f5b6bb1edbf303d5722286a0a54011",
       classLoaderCache,
-      sbtInterface_0_13_13_,
+      sbtInterface_0_13_15_,
       scalaCompiler_2_10_6_ClasspathArray
     );
 
-    // com.typesafe.sbt:compiler-interface:0.13.13
-    String[] compilerInterface_0_13_13_ClasspathArray = new String[]{compilerInterface_0_13_13_File, sbtInterface_0_13_13_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    ClassLoader compilerInterface_0_13_13_ = loadDependency(
-      mavenUrl + "/com/typesafe/sbt/compiler-interface/0.13.13/compiler-interface-0.13.13-sources.jar",
-      compilerInterface_0_13_13_File,
-      "691bf88813bb34771c0ca4418d579bb652e1526f",
+    // com.typesafe.sbt:compiler-interface:0.13.15
+    String[] compilerInterface_0_13_15_ClasspathArray = new String[]{compilerInterface_0_13_15_File, sbtInterface_0_13_15_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
+    ClassLoader compilerInterface_0_13_15_ = loadDependency(
+      mavenUrl + "/com/typesafe/sbt/compiler-interface/0.13.15/compiler-interface-0.13.15-sources.jar",
+      compilerInterface_0_13_15_File,
+      "bad996ed4fc3e83b872525e9cd7b80d81b98a324",
       classLoaderCache,
       scalaCompiler_2_10_6_,
-      compilerInterface_0_13_13_ClasspathArray
+      compilerInterface_0_13_15_ClasspathArray
     );
 
-    // com.typesafe.sbt:incremental-compiler:0.13.13
-    String[] incrementalCompiler_0_13_13_ClasspathArray = new String[]{compilerInterface_0_13_13_File, incrementalCompiler_0_13_13_File, sbtInterface_0_13_13_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    ClassLoader incrementalCompiler_0_13_13_ = loadDependency(
-      mavenUrl + "/com/typesafe/sbt/incremental-compiler/0.13.13/incremental-compiler-0.13.13.jar",
-      incrementalCompiler_0_13_13_File,
-      "65008fb90b965ea44d0959b8a2e214df206cda6e",
+    // com.typesafe.sbt:incremental-compiler:0.13.15
+    String[] incrementalCompiler_0_13_15_ClasspathArray = new String[]{compilerInterface_0_13_15_File, incrementalCompiler_0_13_15_File, sbtInterface_0_13_15_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
+    ClassLoader incrementalCompiler_0_13_15_ = loadDependency(
+      mavenUrl + "/com/typesafe/sbt/incremental-compiler/0.13.15/incremental-compiler-0.13.15.jar",
+      incrementalCompiler_0_13_15_File,
+      "95e20d00b25a7aae19838009c11578b7e6b258ad",
       classLoaderCache,
-      compilerInterface_0_13_13_,
-      incrementalCompiler_0_13_13_ClasspathArray
+      compilerInterface_0_13_15_,
+      incrementalCompiler_0_13_15_ClasspathArray
     );
 
-    // com.typesafe.zinc:zinc:0.3.13
-    String[] zinc_0_3_13_ClasspathArray = new String[]{compilerInterface_0_13_13_File, incrementalCompiler_0_13_13_File, sbtInterface_0_13_13_File, zinc_0_3_13_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
-    ClassLoader zinc_0_3_13_ = loadDependency(
-      mavenUrl + "/com/typesafe/zinc/zinc/0.3.13/zinc-0.3.13.jar",
-      zinc_0_3_13_File,
-      "ae0dcd6105d6e87ece2d181c5f0f7a79a966775a",
+    // com.typesafe.zinc:zinc:0.3.15
+    String[] zinc_0_3_15_ClasspathArray = new String[]{compilerInterface_0_13_15_File, incrementalCompiler_0_13_15_File, sbtInterface_0_13_15_File, zinc_0_3_15_File, scalaCompiler_2_10_6_File, scalaLibrary_2_10_6_File, scalaReflect_2_10_6_File};
+    ClassLoader zinc_0_3_15_ = loadDependency(
+      mavenUrl + "/com/typesafe/zinc/zinc/0.3.15/zinc-0.3.15.jar",
+      zinc_0_3_15_File,
+      "12e1f782684f2702e847faa0994eed4711270687",
       classLoaderCache,
-      incrementalCompiler_0_13_13_,
-      zinc_0_3_13_ClasspathArray
+      incrementalCompiler_0_13_15_,
+      zinc_0_3_15_ClasspathArray
     );
 
-    // org.scala-lang:scala-library:2.11.8
-    String[] scalaLibrary_2_11_8_ClasspathArray = new String[]{scalaLibrary_2_11_8_File};
-    ClassLoader scalaLibrary_2_11_8_ = loadDependency(
-      mavenUrl + "/org/scala-lang/scala-library/2.11.8/scala-library-2.11.8.jar",
-      scalaLibrary_2_11_8_File,
-      "ddd5a8bced249bedd86fb4578a39b9fb71480573",
+    // org.scala-lang:scala-library:2.11.11
+    String[] scalaLibrary_2_11_11_ClasspathArray = new String[]{scalaLibrary_2_11_11_File};
+    ClassLoader scalaLibrary_2_11_11_ = loadDependency(
+      mavenUrl + "/org/scala-lang/scala-library/2.11.11/scala-library-2.11.11.jar",
+      scalaLibrary_2_11_11_File,
+      "e283d2b7fde6504f6a86458b1f6af465353907cc",
       classLoaderCache,
       rootClassLoader,
-      scalaLibrary_2_11_8_ClasspathArray
+      scalaLibrary_2_11_11_ClasspathArray
     );
 
     // org.scala-lang.modules:scala-xml_2.11:1.0.6
-    String[] scalaXml_1_0_6_ClasspathArray = new String[]{scalaXml_1_0_6_File, scalaLibrary_2_11_8_File};
+    String[] scalaXml_1_0_6_ClasspathArray = new String[]{scalaXml_1_0_6_File, scalaLibrary_2_11_11_File};
     ClassLoader scalaXml_1_0_6_ = loadDependency(
       mavenUrl + "/org/scala-lang/modules/scala-xml_2.11/1.0.6/scala-xml_2.11-1.0.6.jar",
       scalaXml_1_0_6_File,
       "4ebd108453e6455351c0ec50d32509ae1154fdb1",
       classLoaderCache,
-      scalaLibrary_2_11_8_,
+      scalaLibrary_2_11_11_,
       scalaXml_1_0_6_ClasspathArray
     );
 
     classLoader = scalaXml_1_0_6_;
     classpathArray = scalaXml_1_0_6_ClasspathArray;
 
-    zinc = zinc_0_3_13_;
+    zinc = zinc_0_3_15_;
 
-    scalaCompiler_File = scalaCompiler_2_11_8_File;
-    scalaLibrary_File = scalaLibrary_2_11_8_File;
-    scalaReflect_File = scalaReflect_2_11_8_File;
-    sbtInterface_File = sbtInterface_0_13_13_File;
-    compilerInterface_File = compilerInterface_0_13_13_File;
+    scalaCompiler_File = scalaCompiler_2_11_11_File;
+    scalaLibrary_File = scalaLibrary_2_11_11_File;
+    scalaReflect_File = scalaReflect_2_11_11_File;
+    sbtInterface_File = sbtInterface_0_13_15_File;
+    compilerInterface_File = compilerInterface_0_13_15_File;
   }
 }
diff --git a/nailgun_launcher/build/build.scala b/nailgun_launcher/build/build.scala
new file mode 100644
index 00000000..f1e25af4
--- /dev/null
+++ b/nailgun_launcher/build/build.scala
@@ -0,0 +1,11 @@
+package cbt_build.nailgun_launcher
+import cbt._
+class Build(val context: Context) extends BaseBuild{
+  // nailgun launcher doesn't need Scala. In fact not
+  // removing it here will lead to conflicts when
+  // is is loaded as a DirectoryDependency in
+  // loadCustomBuildWithDifferentCbtVersion
+  // because depending on a specific scala version conflicts
+  // with whatever scala version the host cbt runs
+  override def dependencies = Seq()
+}
diff --git a/stage1/ClassPath.scala b/stage1/ClassPath.scala
index b13bdaf7..8dcec0ce 100644
--- a/stage1/ClassPath.scala
+++ b/stage1/ClassPath.scala
@@ -14,7 +14,7 @@ case class ClassPath(files: Seq[File] = Seq()){
   private val nonExisting = files.distinct.filterNot(_.exists)
   assert(
     nonExisting.isEmpty,
-    "Classpath contains entires that don't exist on disk:\n" ++ nonExisting.mkString("\n") ++ "\nin classpath:\n"++string
+    "Classpath contains entries that don't exist on disk:\n" ++ nonExisting.mkString("\n") ++ "\nin classpath:\n"++string
   )
 
   def +:(file: File) = ClassPath(file +: files)
diff --git a/stage1/Stage1Lib.scala b/stage1/Stage1Lib.scala
index 89e52b6b..422aa005 100644
--- a/stage1/Stage1Lib.scala
+++ b/stage1/Stage1Lib.scala
@@ -109,8 +109,8 @@ class Stage1Lib( logger: Logger ) extends
           None
         }
       }.getOrElse{
-        System.err.println("System.console() == null. Use `cbt direct <task>` or see https://github.com/cvogt/cbt/issues/236")
-        None
+        throw new Exception("System.console() == null. Use `cbt direct <task>` or see https://github.com/cvogt/cbt/issues/236")
+        //None
       }
     }
   }
diff --git a/stage1/resolver.scala b/stage1/resolver.scala
index 0da8f6fe..3d7463d5 100644
--- a/stage1/resolver.scala
+++ b/stage1/resolver.scala
@@ -88,9 +88,11 @@ trait DependencyImplementation extends Dependency{
     throw new RuntimeException( "No main class found in " + this )
   )
 
+  def mainClasses = classes.filter( lib.findMain(_).nonEmpty )
+
   def mainClass = lib.pickOne(
     "Which one do you want to run?",
-    classes.filter( lib.findMain(_).nonEmpty )
+    mainClasses
   )( _.name.stripSuffix( "$" ) )
 
   def classes = exportedClasspath.files.flatMap(
@@ -294,7 +296,7 @@ case class BoundMavenDependency(
     file
   }
 
-  private def resolveHash(suffix: String, useClassifier: Boolean) = {
+  private def resolveHash(suffix: String, useClassifier: Boolean): String = {
     val path = resolve( suffix ++ ".sha1", None, useClassifier ).toPath
     Option( classLoaderCache.hashMap.get("hash:"+path) ).map(_.asInstanceOf[String]).getOrElse{
       val result = Files.readAllLines(
diff --git a/test/library-test/build/build.scala b/test/library-test/build/build.scala
index f16f0c2e..85615046 100644
--- a/test/library-test/build/build.scala
+++ b/test/library-test/build/build.scala
@@ -1,6 +1,6 @@
 import cbt._
 
-// cbt:https://github.com/cvogt/cbt.git#f11b8318b85f16843d8cfa0743f64c1576614ad6
+// cbt:https://github.com/cvogt/cbt.git#2ab3402e4899e722905a3a5a0825c5af38706303
 class Build(val context: Context) extends BaseBuild with PackageJars{
   def groupId = "cbt.test"
   def version = "0.1"
diff --git a/test/simple-fixed-cbt/build/build.scala b/test/simple-fixed-cbt/build/build.scala
index 2ce1d02d..e2fa6554 100644
--- a/test/simple-fixed-cbt/build/build.scala
+++ b/test/simple-fixed-cbt/build/build.scala
@@ -1,6 +1,6 @@
 import cbt._
 
-// cbt:https://github.com/cvogt/cbt.git#f11b8318b85f16843d8cfa0743f64c1576614ad6
+// cbt:https://github.com/cvogt/cbt.git#2ab3402e4899e722905a3a5a0825c5af38706303
 class Build(val context: cbt.Context) extends PackageJars{
   override def dependencies = super.dependencies ++ Seq(
     DirectoryDependency( context.cbtHome ++ "/test/library-test" )
diff --git a/test/simple-fixed/build/build.scala b/test/simple-fixed/build/build.scala
index 0215c432..12671be2 100644
--- a/test/simple-fixed/build/build.scala
+++ b/test/simple-fixed/build/build.scala
@@ -5,7 +5,7 @@ class Build(context: cbt.Context) extends BasicBuild(context){
     super.dependencies
     ++
     Seq(
-      GitDependency("https://github.com/cvogt/cbt.git", "f11b8318b85f16843d8cfa0743f64c1576614ad6", Some("test/library-test"))
+      GitDependency("https://github.com/cvogt/cbt.git", "2ab3402e4899e722905a3a5a0825c5af38706303", Some("test/library-test"))
     )
   )
 }