flex-bison issue

[Krishna Mohan D]

Hi,
   I  am trying to port lex-yacc files to flex-bison.  I had faced some
issues and could resolve few of them.  I am trying some sample programs on
flex-bison but they are not working as expected.

How do I use the bison trace option? Is it enough if I define YYDEBUG?  Or
do I need to include any statements in test.y file?  Please help.

Thanks and regards,
Krishna