Q: VS2012 Debug stepping into PL/SQL I am trying to Debug Pl/SQL packaged procedure through vs2012.
The Studio output shows that
PL/SQL Debugger will use host: nnn.nnn.nn.nn and port: 65000 for Oracle Application Debugging

When the application starts and when the c# code hits the break point ExecuteNoneQuery the output shows
A database has connected to the PL/SQL Debugger on host nnn.nnn.nn and port:65000

but the debugger does not hit break point set in the PL/SQL code ..
What did I do wrong ?

A: There's quite a few steps needed to get PL/SQL debugging working for the first time. Among them are debugging permissions, compiling with debug metadata, setting the Options page.... it sounds to me like you did not compile with debug metadata.
I have two suggestions:
1) Read the Debugging Setup Checklist in the PL/SQL Debugger section of the Oracle Developer Tools online help.
2) Work through this walkthrough:
https://apex.oracle.com/pls/apex/f?p=44785:24:8435468845634:::24:P24_CONTENT_ID,P24_PROD_SECTION_GRP_ID,P24_PREV_PAGE:10191,,24

A: Hmm... ! Interesting encounter..
The packaged.procedure I was trying to debug was initially developed with Oracele Sql Developer.  The same package was brought into VS2012 on connecting to the Oracle database.
And re-compiled with Vs2012 Oracle tools.
Comments like 
/*--- here comes the santa -----
 -----------end of santa------------------*/

were fine under Oracle Developer.
But under VS2012 Oracle tools the parser is not paring /* and */ because of the -- appearing before the end comment */
All I had to do was this
/*--- here comes the santa -----
     -----------end of santa------------------
*/

