games/stratagus: Build with lua51.

Signed-off-by: B. Watson <urchlay@slackware.uk>

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>

games/stratagus/README

@@ -11,3 +11,9 @@ the stratagus and wargus version numbers match. This shouldn't be a
 problem (both will be updated at SBo at the same time, when needed).
 
 Stratagus was formerly known as FreeCraft and ALE Clone.
+
+Upgrade note: Why haven't I updated this in 6 years? It's because
+newer versions of wargus and stratagus are unable to play the game
+using the data files from the Warcraft II CD that I bought in the
+1990s. I assume I'm not the only one using the old version of the
+game, either.

games/stratagus/stratagus.SlackBuild

@@ -25,13 +25,14 @@
 #   want to play with it, add -DENABLE_TOUCHSCREEN=ON in the cmake
 #   command below.
 
+# 20241020 bkw: BUILD=2, fix for new lua51 build.
 # 20180915 bkw: updated for v2.4.1
 
 cd $(dirname $0) ; CWD=$(pwd)
 
 PRGNAM=stratagus
 VERSION=${VERSION:-2.4.1}
-BUILD=${BUILD:-1}
+BUILD=${BUILD:-2}
 TAG=${TAG:-_SBo}
 PKGTYPE=${PKGTYPE:-tgz}
 
@@ -88,6 +89,7 @@ sed -i 's,"_C_," _C_,' src/ai/ai_plan.cpp src/stratagus/script.cpp
 mkdir -p build
 cd build
   cmake \
+    -DLUA_INCLUDE_DIR=/usr/include/lua5.1 \
     -DENABLE_DOC=ON \
     -DENABLE_DEV=ON \
     -DENABLE_STRIP=ON \