try to protect from bad bb stuff

SConstruct

@@ -19,6 +19,9 @@ import shutil
 import urllib
 import urllib2
 import buildscripts
+import buildscripts.bb
+
+buildscripts.bb.checkOk()
 
 # --- options ----
 AddOption('--prefix',

buildscripts/bb.py

@@ -0,0 +1,23 @@
+# bb tools
+
+import os
+import re
+
+def checkOk():
+    dir = os.getcwd()
+    m = re.compile( ".*/.*_V(\d+\.\d+)/mongo" ).findall( dir )
+    if len(m) == 0:
+        return
+    if len(m) > 1:
+        raise Exception( "unexpected: " + str(m) )
+    
+    m = "v" + m[0]
+    print( m )
+    print( "excpted version [" + m + "]" )
+
+    from subprocess import Popen, PIPE
+    diff = Popen( [ "git", "diff", "origin/v1.2" ], stdout=PIPE ).communicate()[ 0 ]
+    if len(diff) > 0:
+        print( diff )
+        raise Exception( "build bot broken?" )
+