Why does my Mac (OS X 10.7.3) have an old version (2.3) of Gnu Bison?

Question

The version of GNU Bison on my mac is 2.3 but I know that Bison 2.5 was released long ago. The book Flex & Bison uses version 2.5.

Should I upgrade to 2.5 m

Answer 1

I had the same issue MacOSX 10.9.5.

After doing:

brew install bison

I added this to my bash profile:

export PATH=/usr/local/Cellar/bison/3.0.4/bin:$PATH

(by the time you read this, your version may be different from 3.0.4) And after I restarted the Terminal it picked up the new version of Bison when I did bison -V