From a4978ed33dc57104e5e57b1263109e99cc1a5f6d Mon Sep 17 00:00:00 2001
From: Alexandre Duret-Lutz <adl@lrde.epita.fr>
Date: Wed, 23 Sep 2020 11:35:11 +0200
Subject: [PATCH] Update HACKING

Fixes #427 and #429.

* HACKING: Mention dot2tex and update Flex.
---
 HACKING | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/HACKING b/HACKING
index f41d7e274..6988c011b 100644
--- a/HACKING
+++ b/HACKING
@@ -24,7 +24,7 @@ since the generated files they produce are distributed.)
   GNU Autoconf >= 2.61
   GNU Automake >= 1.11
   GNU Libtool >= 2.4
-  GNU Flex (the version seems to matters, we used 2.5.35)
+  GNU Flex >= 2.6
   GNU Bison >= 3.0
   GNU Emacs (preferably >= 24 but it may work with older versions)
   org-mode >= 9.1 (the version that comes bundled with your emacs
@@ -59,6 +59,7 @@ only for certain operations (like releases):
   ltl2dstar likewise
   ltl3dra   likewise
   spin      likewise
+  dot2tex   used for an example in the documentation and in one test
   glucose >= 3.0  likewise
   lbtt >= 1.2.1a  used in the test suite (ltlcross is now more
             powerful, but additional tests do not hurt)