Clarify required bison version.

Reported by Roger Mc Murtrie <rogermc@grapevine.com.au>
at <https://savannah.gnu.org/bugs/?47484>.

* HACKING: Mention minimum version of bison.

diff --git a/HACKING b/HACKING
index 321ec249555d9790a17ffe2a58d0251b5bab6dad..295b2447dd1e86024f6581b47002d1886535b26a 100644 (file)
--- a/HACKING
+++ b/HACKING
@@ -23,7 +23,7 @@ You will need reasonably recent versions of the build tools:
     + Homepage:
       http://www.gnu.org/software/m4/
 
-  * GNU bison
+  * GNU bison 2.7 or newer
     + Homepage:
       http://www.gnu.org/software/bison/