diff --git a/frege-interpreter-core/pom.xml b/frege-interpreter-core/pom.xml
index fdae57f..8aeaaf2 100644
--- a/frege-interpreter-core/pom.xml
+++ b/frege-interpreter-core/pom.xml
@@ -6,7 +6,7 @@
     <parent>
         <groupId>frege</groupId>
         <artifactId>frege-interpreter</artifactId>
-        <version>1.0.2-SNAPSHOT</version>
+        <version>1.0.2</version>
     </parent>
     <artifactId>frege-interpreter-core</artifactId>
     <packaging>jar</packaging>
diff --git a/frege-interpreter-core/src/main/frege/frege/interpreter/FregeInterpreter.fr b/frege-interpreter-core/src/main/frege/frege/interpreter/FregeInterpreter.fr
index 5723c87..00f326d 100644
--- a/frege-interpreter-core/src/main/frege/frege/interpreter/FregeInterpreter.fr
+++ b/frege-interpreter-core/src/main/frege/frege/interpreter/FregeInterpreter.fr
@@ -8,6 +8,7 @@ import Compiler.Scanner hiding (main, is, interpret)
 import Compiler.Main(stdOptions, format,
   make, parsePass, postTrue, getOperators)
 import Compiler.GUtil as GUtil()
+import frege.compiler.types.Flags as Compilerflags(Flag, Flags)
 import Lib.PP(TEXT)
 import Data.List
 import Data.Maybe
@@ -102,7 +103,8 @@ standardOptions classLoader = do
                 thisPos  = Position.null,
                 nsPos = Tree.empty,
                 thisPack = Pack.new "",
-                errors  = 0,
+                numErrors  = 0,
+                resErrors = 0,
                 messages = [],
                 cancelled = return false,
                 nextPass = 1,
@@ -314,7 +316,7 @@ runpass (pass,description,post) = do
         postconditionHolds <- if state.errors == 0 then post else stio true
         unless (postconditionHolds) do
             doio (state.stderr.println "FATAL: post condition violated")
-            changeST Global.{sub <- SubSt.{errors <- (1+)}}
+            changeST Global.{sub <- SubSt.{numErrors <- (1+)}}
         stio ()
 
 derive Show Severity
@@ -628,7 +630,7 @@ showThrowableCause' depth t = maybe (showNative t) (showThrowableCause' (pred de
 -- Native Definitions
 
 data MemoryJavaCompiler = native frege.interpreter.javasupport.MemoryJavaCompiler where
-  native new :: Mutable s (JMap String ByteArr) -> STMutable s MemoryJavaCompiler
+  native new :: Mutable s (JMap String ByteArray) -> STMutable s MemoryJavaCompiler
               | Mutable s InterpreterClassLoader -> STMutable s MemoryJavaCompiler
   native compile :: Mutable s MemoryJavaCompiler -> String -> String -> STMutable s JavaCompilationInfo
   native classLoader :: Mutable s MemoryJavaCompiler ->  STMutable s InterpreterClassLoader
@@ -636,8 +638,8 @@ data MemoryJavaCompiler = native frege.interpreter.javasupport.MemoryJavaCompile
 data InterpreterClassLoader = native frege.interpreter.javasupport.InterpreterClassLoader where
   native new :: () -> STMutable s InterpreterClassLoader
               | ClassLoader -> IOMutable InterpreterClassLoader
-              | Mutable s (JMap String ByteArr) -> STMutable s InterpreterClassLoader
-  pure native classes :: InterpreterClassLoader -> JMap String ByteArr
+              | Mutable s (JMap String ByteArray) -> STMutable s InterpreterClassLoader
+  pure native classes :: InterpreterClassLoader -> JMap String ByteArray
 
   private defaultClassLoaderST = do
                     loader <- InterpreterClassLoader.new ()
@@ -652,9 +654,13 @@ data JavaCompilationInfo = native frege.interpreter.javasupport.CompilationInfo
   native isSuccess :: Mutable s JavaCompilationInfo -> ST s Bool
   native errorsAsString :: Mutable s JavaCompilationInfo -> ST s String
   native classLoader :: MutableIO JavaCompilationInfo -> IO ClassLoader
-  native classes :: Mutable s JavaCompilationInfo -> STMutable s (JMap String ByteArr)
+  native classes :: Mutable s JavaCompilationInfo -> STMutable s (JMap String ByteArray)
 
-data ByteArr = mutable native "byte[]"
+
+data Byte = pure native byte
+derive ArrayElement Byte
+
+type ByteArray = JArray Byte
 
 data JMap k v = native java.util.Map where
   native put :: Mutable s (JMap k v) -> k -> v -> ST s ()
@@ -671,43 +677,12 @@ native fieldValue frege.interpreter.javasupport.JavaUtils.fieldValue ::
   String -> String -> InterpreterClassLoader -> ST s (Maybe a)
 
 native sandboxFieldValue frege.interpreter.javasupport.JavaUtils.sandboxFieldValue ::
-  String -> String -> InterpreterClassLoader -> ST s (Maybe a)
+  String -> String -> String -> StringWriter -> StringWriter -> InterpreterClassLoader -> IO (Maybe a)
 
 pure native longToString Long.toString :: Long -> Int -> String
 
 pure native showNative String.valueOf :: a -> String
 pure native throwableCause getCause :: Throwable -> Maybe Throwable
 
-
-data ObjectArr = native "java.lang.Object[]" where
-    --- make a new mutable Object array
-    native new    "java.lang.Object[]"
-                                                :: Int -> STMutable s ObjectArr
-    native getAt  "frege.runtime.Array.<java.lang.Object>arrayGet"
-                                                :: Mutable s ObjectArr -> Int -> ST s (Maybe Object)
-    native setAt  "frege.runtime.Array.<java.lang.Object>arraySet"
-                                                :: Mutable s ObjectArr -> Int -> Object -> ST s ()
-    pure native frozenGetAt "frege.runtime.Array.<java.lang.Object>arrayGet"
-                                                :: ObjectArr -> Int -> Maybe Object
-    --- use this only if it is absolutely sure that there are no nulls in the array
-    pure native elemAt "frege.runtime.Array.<java.lang.Object>arrayGet"
-                                                :: ObjectArr -> Int -> Object
-    --- the length of the array
-    pure native length "frege.runtime.Array.<java.lang.Object>arrayLen"
-                                                :: ObjectArr -> Int
-    toList (a::ObjectArr) = elems a 0
-        where
-            elems (a::ObjectArr) i
-                | i < a.length = case frozenGetAt a i of
-                    Just s  -> s:elems a (i+1)
-                    Nothing -> elems a (i+1)
-                | otherwise = []
-
-    fromListST :: [Object] -> STMutable u ObjectArr
-    fromListST objects = (ObjectArr.new objects.length >>= loop 0 objects) where
-        loop j (x:xs) arr = do ObjectArr.setAt arr j x; loop (j+1) xs arr
-        loop j []     arr = return arr
-    fromList objects = ST.run (fromListST objects >>= readonly id)
-
 data Method = pure native java.lang.reflect.Method where
   pure native getName :: Method -> String
diff --git a/frege-interpreter-java-support/pom.xml b/frege-interpreter-java-support/pom.xml
index a4863da..a2a0aa3 100644
--- a/frege-interpreter-java-support/pom.xml
+++ b/frege-interpreter-java-support/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>frege</groupId>
     <artifactId>frege-interpreter</artifactId>
-    <version>1.0.2-SNAPSHOT</version>
+    <version>1.0.2</version>
   </parent>
   <artifactId>frege-interpreter-java-support</artifactId>
   <packaging>jar</packaging>
diff --git a/frege-interpreter-java-support/src/main/java/frege/interpreter/javasupport/JavaUtils.java b/frege-interpreter-java-support/src/main/java/frege/interpreter/javasupport/JavaUtils.java
index a40335a..a4aca01 100644
--- a/frege-interpreter-java-support/src/main/java/frege/interpreter/javasupport/JavaUtils.java
+++ b/frege-interpreter-java-support/src/main/java/frege/interpreter/javasupport/JavaUtils.java
@@ -1,6 +1,13 @@
 package frege.interpreter.javasupport;
 
+import frege.runtime.Runtime;
+
+import java.io.BufferedReader;
 import java.io.FilePermission;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringReader;
+import java.io.StringWriter;
 import java.lang.reflect.Field;
 import java.security.Permission;
 import java.util.Map;
@@ -24,15 +31,28 @@ public static Object fieldValue(final String className,
 
     public static Object sandboxFieldValue(final String className,
                                            final String variableName,
+                                           final String stdinStr,
+                                           final StringWriter outWriter,
+                                           final StringWriter errWriter,
                                            final InterpreterClassLoader loader) {
         return sandbox(new FutureTask<>(new Callable<Object>() {
             @Override
             public Object call() throws Exception {
+                prepareRuntime(stdinStr, outWriter, errWriter);
                 return fieldValue(className, variableName, loader);
             }
         }), 5, TimeUnit.SECONDS);
     }
 
+    private static void prepareRuntime(final String stdinStr, final StringWriter outWriter, final StringWriter errWriter) {
+        final BufferedReader stdin = new BufferedReader(new StringReader(stdinStr + "\n"));
+        final PrintWriter stdout = new PrintWriter(outWriter);
+        final PrintWriter stderr = new PrintWriter(errWriter);
+        Runtime.stdin.set(stdin);
+        Runtime.stdout.set(stdout);
+        Runtime.stderr.set(stderr);
+    }
+
     public static <V> V sandbox(final FutureTask<V> task,
                                     final long timeout,
                                     final TimeUnit unit
diff --git a/frege-script-engine/pom.xml b/frege-script-engine/pom.xml
index 9850b9c..f3ade00 100644
--- a/frege-script-engine/pom.xml
+++ b/frege-script-engine/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>frege</groupId>
     <artifactId>frege-interpreter</artifactId>
-    <version>1.0.2-SNAPSHOT</version>
+    <version>1.0.2</version>
   </parent>
   <groupId>frege</groupId>
   <artifactId>frege-script-engine</artifactId>
diff --git a/pom.xml b/pom.xml
index 250400a..9bf054a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
   <groupId>frege</groupId>
   <artifactId>frege-interpreter</artifactId>
   <packaging>pom</packaging>
-  <version>1.0.2-SNAPSHOT</version>
+  <version>1.0.2</version>
   <name>frege-interpreter</name>
   <url>https://github.com/Frege/frege-interpreter</url>
   <modules>
@@ -15,7 +15,7 @@
   </modules>
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <frege.version>3.21.402-g0b89544</frege.version>
+    <frege.version>3.21.440-gd7ba043</frege.version>
     <frege.plugin.version>1.0.5</frege.plugin.version>
     <ecj.version>4.2.2</ecj.version>
   </properties>