diff --git a/main.py b/main.py
index 47f083d..6736abc 100755
--- a/main.py
+++ b/main.py
@@ -45,6 +45,7 @@
 from subcmds.version import Version
 from editor import Editor
 from error import DownloadError
+from error import InvalidProjectGroupsError
 from error import ManifestInvalidRevisionError
 from error import ManifestParseError
 from error import NoManifestException
@@ -173,6 +174,12 @@
       else:
         print('error: no project in current directory', file=sys.stderr)
       result = 1
+    except InvalidProjectGroupsError as e:
+      if e.name:
+        print('error: project group must be enabled for project %s' % e.name, file=sys.stderr)
+      else:
+        print('error: project group must be enabled for the project in the current directory', file=sys.stderr)
+      result = 1
     finally:
       elapsed = time.time() - start
       hours, remainder = divmod(elapsed, 3600)
diff --git a/subcmds/forall.py b/subcmds/forall.py
index ebc8bec..b93cd6d 100644
--- a/subcmds/forall.py
+++ b/subcmds/forall.py
@@ -151,11 +151,15 @@
     attributes that we need.
 
     """
+    if not self.manifest.IsMirror:
+      lrev = project.GetRevisionId()
+    else:
+      lrev = None
     return {
       'name': project.name,
       'relpath': project.relpath,
       'remote_name': project.remote.name,
-      'lrev': project.GetRevisionId(),
+      'lrev': lrev,
       'rrev': project.revisionExpr,
       'annotations': dict((a.name, a.value) for a in project.annotations),
       'gitdir': project.gitdir,
@@ -201,6 +205,13 @@
     mirror = self.manifest.IsMirror
     rc = 0
 
+    smart_sync_manifest_name = "smart_sync_override.xml"
+    smart_sync_manifest_path = os.path.join(
+      self.manifest.manifestProject.worktree, smart_sync_manifest_name)
+
+    if os.path.isfile(smart_sync_manifest_path):
+      self.manifest.Override(smart_sync_manifest_path)
+
     if not opt.regex:
       projects = self.GetProjects(args)
     else:
diff --git a/subcmds/sync.py b/subcmds/sync.py
index b4546c1..ec333ae 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -517,6 +517,9 @@
       self.manifest.Override(opt.manifest_name)
 
     manifest_name = opt.manifest_name
+    smart_sync_manifest_name = "smart_sync_override.xml"
+    smart_sync_manifest_path = os.path.join(
+      self.manifest.manifestProject.worktree, smart_sync_manifest_name)
 
     if opt.smart_sync or opt.smart_tag:
       if not self.manifest.manifest_server:
@@ -583,17 +586,16 @@
           [success, manifest_str] = server.GetManifest(opt.smart_tag)
 
         if success:
-          manifest_name = "smart_sync_override.xml"
-          manifest_path = os.path.join(self.manifest.manifestProject.worktree,
-                                       manifest_name)
+          manifest_name = smart_sync_manifest_name
           try:
-            f = open(manifest_path, 'w')
+            f = open(smart_sync_manifest_path, 'w')
             try:
               f.write(manifest_str)
             finally:
               f.close()
-          except IOError:
-            print('error: cannot write manifest to %s' % manifest_path,
+          except IOError as e:
+            print('error: cannot write manifest to %s:\n%s'
+                  % (smart_sync_manifest_path, e),
                   file=sys.stderr)
             sys.exit(1)
           self._ReloadManifest(manifest_name)
@@ -610,6 +612,13 @@
               % (self.manifest.manifest_server, e.errcode, e.errmsg),
               file=sys.stderr)
         sys.exit(1)
+    else:  # Not smart sync or smart tag mode
+      if os.path.isfile(smart_sync_manifest_path):
+        try:
+          os.remove(smart_sync_manifest_path)
+        except OSError as e:
+          print('error: failed to remove existing smart sync override manifest: %s' %
+                e, file=sys.stderr)
 
     rp = self.manifest.repoProject
     rp.PreSync()