diff --git a/maven-core/src/main/java/org/apache/maven/lifecycle/internal/LifecycleModuleBuilder.java b/maven-core/src/main/java/org/apache/maven/lifecycle/internal/LifecycleModuleBuilder.java
index df7f67458f..d987a30709 100644
--- a/maven-core/src/main/java/org/apache/maven/lifecycle/internal/LifecycleModuleBuilder.java
+++ b/maven-core/src/main/java/org/apache/maven/lifecycle/internal/LifecycleModuleBuilder.java
@@ -124,12 +124,22 @@ public void buildProject( MavenSession session, MavenSession rootSession, Reacto
 
             eventCatapult.fire( ExecutionEvent.Type.ProjectSucceeded, session, null );
         }
-        catch ( Exception e )
+        catch ( Throwable t )
         {
-            builderCommon.handleBuildError( reactorContext, rootSession, session, currentProject, e, buildStartTime );
+            builderCommon.handleBuildError( reactorContext, rootSession, session, currentProject, t, buildStartTime );
 
             projectExecutionListener.afterProjectExecutionFailure( new ProjectExecutionEvent( session, currentProject,
-                                                                                              e ) );
+                                                                                              t ) );
+
+            // rethrow original errors and runtime exceptions
+            if ( t instanceof RuntimeException )
+            {
+                throw (RuntimeException) t;
+            }
+            if ( t instanceof Error )
+            {
+                throw (Error) t;
+            }
         }
         finally
         {
diff --git a/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/BuilderCommon.java b/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/BuilderCommon.java
index 81109022b9..691c9810af 100644
--- a/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/BuilderCommon.java
+++ b/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/BuilderCommon.java
@@ -19,7 +19,6 @@
  * under the License.
  */
 
-import org.apache.maven.InternalErrorException;
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.execution.BuildFailure;
 import org.apache.maven.execution.ExecutionEvent;
@@ -139,23 +138,28 @@ public MavenExecutionPlan resolveBuildPlan( MavenSession session, MavenProject p
     }
 
     public void handleBuildError( final ReactorContext buildContext, final MavenSession rootSession,
-                                  final MavenSession currentSession, final MavenProject mavenProject, Exception e,
+                                  final MavenSession currentSession, final MavenProject mavenProject, Throwable t,
                                   final long buildStartTime )
     {
-        if ( e instanceof RuntimeException )
+        // record the error and mark the project as failed
+        long buildEndTime = System.currentTimeMillis();
+        buildContext.getResult().addException( t );
+        buildContext.getResult().addBuildSummary( new BuildFailure( mavenProject, buildEndTime - buildStartTime, t ) );
+
+        // notify listeners about "soft" project build failures only
+        if ( t instanceof Exception && !( t instanceof RuntimeException ) )
         {
-            e = new InternalErrorException( "Internal error: " + e, e );
+            eventCatapult.fire( ExecutionEvent.Type.ProjectFailed, currentSession, null, (Exception) t );
         }
 
-        buildContext.getResult().addException( e );
-
-        long buildEndTime = System.currentTimeMillis();
-
-        buildContext.getResult().addBuildSummary( new BuildFailure( mavenProject, buildEndTime - buildStartTime, e ) );
-
-        eventCatapult.fire( ExecutionEvent.Type.ProjectFailed, currentSession, null, e );
-
-        if ( MavenExecutionRequest.REACTOR_FAIL_NEVER.equals( rootSession.getReactorFailureBehavior() ) )
+        // reactor failure modes
+        if ( t instanceof RuntimeException || !( t instanceof Exception ) )
+        {
+            // fail fast on RuntimeExceptions, Errors and "other" Throwables
+            // assume these are system errors and further build is meaningless
+            buildContext.getReactorBuildStatus().halt();
+        }
+        else if ( MavenExecutionRequest.REACTOR_FAIL_NEVER.equals( rootSession.getReactorFailureBehavior() ) )
         {
             // continue the build
         }
@@ -170,8 +174,8 @@ else if ( MavenExecutionRequest.REACTOR_FAIL_FAST.equals( rootSession.getReactor
         }
         else
         {
-            throw new IllegalArgumentException(
-                "invalid reactor failure behavior " + rootSession.getReactorFailureBehavior() );
+            logger.error( "invalid reactor failure behavior " + rootSession.getReactorFailureBehavior() );
+            buildContext.getReactorBuildStatus().halt();
         }
     }
 
diff --git a/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/multithreaded/MultiThreadedBuilder.java b/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/multithreaded/MultiThreadedBuilder.java
index 88fa81b1fa..906e5e7509 100644
--- a/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/multithreaded/MultiThreadedBuilder.java
+++ b/maven-core/src/main/java/org/apache/maven/lifecycle/internal/builder/multithreaded/MultiThreadedBuilder.java
@@ -150,6 +150,7 @@ private void multiThreadedProjectTaskSegmentBuild( ConcurrencyDependencyGraph an
             }
             catch ( ExecutionException e )
             {
+                // TODO MNG-5766 changes likely made this redundant 
                 rootSession.getResult().addException( e );
                 break;
             }