added system error code for failed install due to build already present

pym/calculate/lib/datavars.py

@@ -102,6 +102,10 @@ class CommonVariableError(VariableError):
     """Exception for command line"""
 
 
+class BuildAlreadyInstalledError(VariableError):
+    """Exception for install -U when used after a successful install"""
+
+
 def makePath(dirs, mode=755):
     if not path.exists(dirs):
         os.makedirs(dirs, mode)
@@ -1990,7 +1994,8 @@ class DataVars(SimpleDataVars):
                     messages = e.exception_list if e.exception_list else [e]
                     mess = "\n".join((str(x) for x in messages))
                     mapError = {PasswordError: 'pwderror',
-                                CommonVariableError: 'commonerror'}
+                                CommonVariableError: 'commonerror',
+                                BuildAlreadyInstalledError: 'sysinstalled'}
                     for k, v in mapError.items():
                         if (isinstance(e, k) or e.exception_list and
                             all(isinstance(x, k) for x in