Hi,

It seems that the flex has a bug. ( and it still hasn't been corrected apparently as the version I run is 2.5.35)

The following is the solution suggested in the bison info.
     /* Work around an incompatibility in flex (at least versions
        2.5.31 through 2.5.33): it generates code that does
        not conform to C89. See Debian bug 333231
        <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=333231>. */
     # undef yywrap
     # define yywrap() 1

But then why does this problem arise only when I use autotools. I never faced this problem while I was
using a handmade Makefile?

Regards
Gautam