diff --git a/v2/build/errors.py b/v2/build/errors.py
index 83b39e982..8e17a73c0 100644
--- a/v2/build/errors.py
+++ b/v2/build/errors.py
@@ -97,6 +97,10 @@ class Errors:
 
     def __init__(self):
         self.contexts_ = []
+        self._count = 0
+
+    def count(self):
+        return self._count
 
     def push_user_context(self, message, nested=None):
         self.contexts_.append(Context(message, nested))
@@ -117,6 +121,7 @@ class Errors:
         raise ExceptionWithUserContext("unexpected exception", self.contexts_[:],
                                        e, sys.exc_info()[2])    
     def __call__(self, message):
+        self._count = self._count + 1
         raise ExceptionWithUserContext(message, self.contexts_[:], 
                                        stack=traceback.extract_stack())
 
diff --git a/v2/build/targets.py b/v2/build/targets.py
index 39b127a5c..918c23fd6 100644
--- a/v2/build/targets.py
+++ b/v2/build/targets.py
@@ -76,6 +76,8 @@ import re
 import os.path
 import sys
 
+from b2.manager import get_manager
+
 from b2.util.utility import *
 import property, project, virtual_target, property_set, feature, generators, toolset
 from virtual_target import Subvariant
@@ -84,6 +86,8 @@ from b2.util.sequence import unique
 from b2.util import path, bjam_signature
 from b2.build.errors import user_error_checkpoint
 
+import b2.build.build_request as build_request
+
 import b2.util.set
 
 _re_separate_target_from_properties = re.compile (r'^([^<]*)(/(<.*))?$')
@@ -594,10 +598,10 @@ class MainTarget (AbstractTarget):
         d = target.default_build ()
         
         if self.alternatives_ and self.default_build_ != d:
-            raise BaseException ("Default build must be identical in all alternatives\n"
+            get_manager().errors()("default build must be identical in all alternatives\n"
               "main target is '%s'\n"
               "with '%s'\n"
-              "differing from previous default build: '%s'" % (full_name (), d.raw (), self.default_build_.raw ()))
+              "differing from previous default build: '%s'" % (self.full_name (), d.raw (), self.default_build_.raw ()))
 
         else:
             self.default_build_ = d
@@ -687,7 +691,8 @@ class MainTarget (AbstractTarget):
             # to use here.
             compressed = feature.compress_subproperties(property_set.all())
 
-            result = build_request.expand_no_defaults (compressed, defaults_to_apply)
+            result = build_request.expand_no_defaults(
+                b2.build.property_set.create([p]) for p in (compressed + defaults_to_apply))
             
         else:
             result.append (property_set)
diff --git a/v2/build_system.py b/v2/build_system.py
index 1602d5b2e..5bc30c224 100644
--- a/v2/build_system.py
+++ b/v2/build_system.py
@@ -8,6 +8,8 @@
 # Distributed under the Boost Software License, Version 1.0. 
 # (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt) 
 
+
+
 from b2.build.engine import Engine
 from b2.manager import Manager
 from b2.util.path import glob
@@ -432,14 +434,14 @@ def main():
     if "--profiling" in sys.argv:
         import cProfile
         import pstats
-        cProfile.runctx('main_real()', globals(), locals(), "stones.prof")
+        return cProfile.runctx('main_real()', globals(), locals(), "stones.prof")
         
         stats = pstats.Stats("stones.prof")
         stats.strip_dirs()
         stats.sort_stats('time', 'calls')
         stats.print_callers(20)
     else:
-        main_real()
+        return main_real()
 
 def main_real():
 
@@ -852,3 +854,8 @@ def main_real():
         # Prevent automatic update of the 'all' target, now that
         # we have explicitly updated what we wanted.            
         bjam.call("UPDATE")
+
+    if manager.errors().count() == 0:
+        return ["ok"]
+    else:
+        return []
diff --git a/v2/kernel/bootstrap.jam b/v2/kernel/bootstrap.jam
index a629d214f..2a1be1a14 100644
--- a/v2/kernel/bootstrap.jam
+++ b/v2/kernel/bootstrap.jam
@@ -225,7 +225,11 @@ if ! $(dont-build)
         
         module PyBB
         {
-            bootstrap $(root) ;
+            local ok = [ bootstrap $(root) ] ;
+            if ! $(ok)
+            {
+                EXIT ;
+            }            
         }
         
         
diff --git a/v2/kernel/bootstrap.py b/v2/kernel/bootstrap.py
index cc12add11..2e8dd37b7 100644
--- a/v2/kernel/bootstrap.py
+++ b/v2/kernel/bootstrap.py
@@ -21,5 +21,5 @@ def bootstrap(root_path):
     sys.modules["b2"] = m
 
     import b2.build_system
-    b2.build_system.main()
+    return b2.build_system.main()
 
diff --git a/v2/test/default_build.py b/v2/test/default_build.py
index 93d05ae3b..33f2b5bbb 100644
--- a/v2/test/default_build.py
+++ b/v2/test/default_build.py
@@ -42,7 +42,8 @@ with
 differing from previous default build <variant>debug
 
 """
-t.run_build_system("-n --no-error-backtrace", status=1, stdout=expected)
+t.run_build_system("-n --no-error-backtrace", status=1)
+t.fail_test(t.stdout().find("default build must be identical in all alternatives") == -1)
 
 # Test that default-build must be identical in all alternatives. No Error case,
 # empty default build.