[Asterisk-Users] bison/flex version warning

[Mike M]

Hi,

(I seem to be having some trouble getting messages to post on the list so
I may be duplicating an earlier post. Apologies if this is the case.)

I am compiling CVS tip Asterisk on a fresh CentOS 3.4 install.  I got
this warning:

make ast_expr.a
make[1]: Entering directory `/usr/src/asterisk'
bison -v -d --name-prefix=ast_yy ast_expr.y -o ast_expr.c
=================================================================================
NOTE: Using older version of expression parser. To use the newer
version,
NOTE: upgrade to flex 2.5.31 or higher, which can be found at
NOTE: http://sourceforge.net/project/showfiles.php?group_id=72099
=================================================================================

My bison is this: bison (GNU Bison) 1.875c (Which appears to be ancient
because the s/f link above shows the 2.5.31 flex archive date as
2003-03-31).

What's the risk of ignoring this warning?

Rhetorical question: why is CentOS using a moldy old flex/bison package?

Thanks,
--
Mike