diff --git a/java/compiler/impl/src/com/intellij/compiler/server/BuildManager.java b/java/compiler/impl/src/com/intellij/compiler/server/BuildManager.java
index 2afb3b84bea6..b6e26e706010 100644
--- a/java/compiler/impl/src/com/intellij/compiler/server/BuildManager.java
+++ b/java/compiler/impl/src/com/intellij/compiler/server/BuildManager.java
@@ -693,6 +693,9 @@ public class BuildManager implements ApplicationComponent{
     }
 
     cmdLine.addParameter("-Djava.awt.headless=true");
+    if (ApplicationManager.getApplication().isUnitTestMode()) {
+      cmdLine.addParameter("-Dtest.mode=true");
+    }
 
     final String shouldGenerateIndex = System.getProperty(GlobalOptions.GENERATE_CLASSPATH_INDEX_OPTION);
     if (shouldGenerateIndex != null) {
diff --git a/jps/jps-builders/src/org/jetbrains/jps/cmdline/BuildSession.java b/jps/jps-builders/src/org/jetbrains/jps/cmdline/BuildSession.java
index 6e8a3e3b1f42..c441d770a610 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/cmdline/BuildSession.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/cmdline/BuildSession.java
@@ -331,6 +331,11 @@ final class BuildSession implements Runnable, CanceledStatus {
         if (rd != null) {
           pd.fsState.registerDeleted(rd.module, file, rd.isTestRoot, timestamps);
         }
+        else {
+          if (Utils.IS_TEST_MODE) {
+            LOG.info("Skipping deleted path: " + file.getPath());
+          }
+        }
       }
       for (String changed : event.getChangedPathsList()) {
         final File file = new File(changed);
@@ -338,6 +343,11 @@ final class BuildSession implements Runnable, CanceledStatus {
         if (rd != null) {
           pd.fsState.markDirty(file, rd, timestamps);
         }
+        else {
+          if (Utils.IS_TEST_MODE) {
+            LOG.info("Skipping dirty path: " + file.getPath());
+          }
+        }
       }
     }
 
diff --git a/jps/jps-builders/src/org/jetbrains/jps/incremental/Utils.java b/jps/jps-builders/src/org/jetbrains/jps/incremental/Utils.java
index 60953804d7a1..2b553d8e784d 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/incremental/Utils.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/incremental/Utils.java
@@ -20,6 +20,7 @@ import java.util.*;
 public class Utils {
   public static final Key<Map<String, Collection<String>>> REMOVED_SOURCES_KEY = Key.create("_removed_sources_");
   private static volatile File ourSystemRoot = new File(System.getProperty("user.home", ".idea-build"));
+  public static final boolean IS_TEST_MODE = Boolean.parseBoolean(System.getProperty("test.mode", "false"));
 
   private Utils() {
   }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/BuildFSState.java b/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/BuildFSState.java
index 303f7aab6870..6ff72be64f79 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/BuildFSState.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/BuildFSState.java
@@ -1,5 +1,6 @@
 package org.jetbrains.jps.incremental.fs;
 
+import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.io.FileUtil;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jps.CompilerExcludes;
@@ -8,6 +9,7 @@ import org.jetbrains.jps.ModuleChunk;
 import org.jetbrains.jps.incremental.CompileContext;
 import org.jetbrains.jps.incremental.CompileScope;
 import org.jetbrains.jps.incremental.FileProcessor;
+import org.jetbrains.jps.incremental.Utils;
 import org.jetbrains.jps.incremental.storage.Timestamps;
 
 import java.io.File;
@@ -21,6 +23,7 @@ import java.util.Set;
  *         Date: 12/16/11
  */
 public class BuildFSState extends FSState {
+  private static final Logger LOG = Logger.getInstance("#org.jetbrains.jps.incremental.fs.BuildFSState");
 
   private final Set<String> myContextModules = new HashSet<String>();
   private volatile FilesDelta myCurrentRoundDelta;
@@ -143,6 +146,9 @@ public class BuildFSState extends FSState {
               // if the file was modified after the compilation had started,
               // do not save the stamp considering file dirty
               delta.markRecompile(rd.root, rd.isTestRoot, file);
+              if (Utils.IS_TEST_MODE) {
+                LOG.info("Timestamp after compilation started; marking dirty again: " + file.getPath());
+              }
             }
             else {
               marked = true;
@@ -150,6 +156,9 @@ public class BuildFSState extends FSState {
             }
           }
           else {
+            if (Utils.IS_TEST_MODE) {
+              LOG.info("Not affected by compile scope; marking dirty again: " + file.getPath());
+            }
             delta.markRecompile(rd.root, rd.isTestRoot, file);
           }
         }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/FilesDelta.java b/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/FilesDelta.java
index 6834213627d4..9c18a8e89c51 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/FilesDelta.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/incremental/fs/FilesDelta.java
@@ -1,10 +1,12 @@
 package org.jetbrains.jps.incremental.fs;
 
+import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.util.io.IOUtil;
 import gnu.trove.THashSet;
 import gnu.trove.TObjectHashingStrategy;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jps.incremental.Utils;
 
 import java.io.DataInput;
 import java.io.DataOutput;
@@ -14,6 +16,8 @@ import java.util.*;
 
 /** @noinspection SynchronizationOnLocalVariableOrMethodParameter*/
 final class FilesDelta {
+  private static final Logger LOG = Logger.getInstance("#org.jetbrains.jps.incremental.fs.FilesDelta");
+
   private final Set<String> myDeletedProduction = Collections.synchronizedSet(new HashSet<String>());
   private final Set<String> myDeletedTests = Collections.synchronizedSet(new HashSet<String>());
   private final Map<File, Set<File>> mySourcesToRecompile = Collections.synchronizedMap(new HashMap<File, Set<File>>()); // srcRoot -> set of sources
@@ -57,7 +61,11 @@ final class FilesDelta {
       }
       int filesCount = in.readInt();
       while (filesCount-- > 0) {
-        files.add(new File(IOUtil.readString(in)));
+        final File file = new File(IOUtil.readString(in));
+        if (Utils.IS_TEST_MODE) {
+          LOG.info("Loaded " + file.getPath());
+        }
+        files.add(file);
       }
     }
   }
@@ -115,6 +123,10 @@ final class FilesDelta {
   }
 
   private boolean _addToRecompiled(File root, boolean isTestRoot, File file) {
+    if (Utils.IS_TEST_MODE) {
+      LOG.info("Marking dirty: " + file.getPath());
+    }
+
     final Map<File, Set<File>> toRecompile = isTestRoot ? myTestsToRecompile : mySourcesToRecompile;
     Set<File> files;
     synchronized (toRecompile) {
@@ -123,8 +135,8 @@ final class FilesDelta {
         files = createSetOfFiles();
         toRecompile.put(root, files);
       }
+      return files.add(file);
     }
-    return files.add(file);
   }
 
   public void addDeleted(File file, boolean isTest) {
@@ -136,7 +148,11 @@ final class FilesDelta {
       }
     }
     final Set<String> deleted = isTest? myDeletedTests : myDeletedProduction;
-    deleted.add(FileUtil.toCanonicalPath(file.getPath()));
+    final String path = FileUtil.toCanonicalPath(file.getPath());
+    deleted.add(path);
+    if (Utils.IS_TEST_MODE) {
+      LOG.info("Marking deleted: " + path);
+    }
   }
 
   public void clearDeletedPaths(boolean isTest) {
diff --git a/plugins/groovy/rt/src/org/jetbrains/jps/incremental/groovy/GroovyBuilder.java b/plugins/groovy/rt/src/org/jetbrains/jps/incremental/groovy/GroovyBuilder.java
index 093e7182181f..849509f8b625 100644
--- a/plugins/groovy/rt/src/org/jetbrains/jps/incremental/groovy/GroovyBuilder.java
+++ b/plugins/groovy/rt/src/org/jetbrains/jps/incremental/groovy/GroovyBuilder.java
@@ -49,7 +49,9 @@ public class GroovyBuilder extends ModuleLevelBuilder {
   public ModuleLevelBuilder.ExitCode build(final CompileContext context, ModuleChunk chunk) throws ProjectBuildException {
     try {
       final List<File> toCompile = collectChangedFiles(context, chunk);
-      LOG.info((myForStubs ? "stubs" : "groovyc") + ", toCompile=" + toCompile);
+      if (Utils.IS_TEST_MODE) {
+        LOG.info((myForStubs ? "stubs" : "groovyc") + ", toCompile=" + toCompile);
+      }
       if (toCompile.isEmpty()) {
         return ExitCode.NOTHING_DONE;
       }
@@ -108,14 +110,18 @@ public class GroovyBuilder extends ModuleLevelBuilder {
       }
 
       for (CompilerMessage message : handler.getCompilerMessages()) {
-        LOG.info(message.toString());
+        if (Utils.IS_TEST_MODE) {
+          LOG.info(message.toString());
+        }
         context.processMessage(message);
       }
 
 
       List<GroovycOSProcessHandler.OutputItem> compiled = new ArrayList<GroovycOSProcessHandler.OutputItem>();
       for (GroovycOSProcessHandler.OutputItem item : handler.getSuccessfullyCompiled()) {
-        LOG.info("Compiled " + item);
+        if (Utils.IS_TEST_MODE) {
+          LOG.info("Compiled " + item);
+        }
         compiled.add(ensureCorrectOutput(context, chunk, item, generationOutputs, compilerOutput));
       }