Please find a debdiff attached that fixes this.
diff -Nru onscripter-20220816/debian/changelog
onscripter-20220816/debian/changelog
--- onscripter-20220816/debian/changelog 2022-09-16 08:58:27.000000000
+0200
+++ onscripter-20220816/debian/changelog 2025-03-06 23:19:51.000000000
+0100
@@ -1,3 +1,10 @@
+onscripter (20220816-1.1) unstable; urgency=medium
+
+ * Non-maintainer upload.
+ * Build with lua5.1 again. (Closes: #1050630)
+
+ -- Bastian Germann <b...@debian.org> Thu, 06 Mar 2025 23:19:51 +0100
+
onscripter (20220816-1) unstable; urgency=low
* New upstream release.
diff -Nru onscripter-20220816/debian/control onscripter-20220816/debian/control
--- onscripter-20220816/debian/control 2022-01-17 05:39:38.000000000 +0100
+++ onscripter-20220816/debian/control 2025-03-06 23:16:21.000000000 +0100
@@ -6,7 +6,7 @@
dpkg-dev (>= 1.19.0),
libsdl1.2-dev, libavifile-0.7-dev,
libsdl-image1.2-dev, libsdl-mixer1.2-dev, libsdl-ttf2.0-dev,
- libbz2-dev, libjpeg-dev, liblua5.2-dev, libfontconfig1-dev,
+ libbz2-dev, libjpeg-dev, liblua5.1-0-dev, libfontconfig1-dev,
libvorbis-dev [!arm64 !armel !armhf !mips !mipsel],
libvorbisidec-dev [arm64 armel armhf mips mipsel],
libsmpeg-dev [!arm64 !armel !armhf !mips !mipsel],
diff -Nru onscripter-20220816/debian/rules onscripter-20220816/debian/rules
--- onscripter-20220816/debian/rules 2022-01-17 05:39:38.000000000 +0100
+++ onscripter-20220816/debian/rules 2025-03-06 23:18:13.000000000 +0100
@@ -7,7 +7,7 @@
DEB_MP3MAD_FLAG := $(findstring ok installed,$(shell dpkg-query -W
-f='$${Status}' libmad0-dev))
DEB_SMPEG_FLAG := $(findstring ok installed,$(shell dpkg-query -W
-f='$${Status}' libsmpeg-dev))
DEB_FONTCONFIG_FLAG := $(findstring ok installed,$(shell dpkg-query -W
-f='$${Status}' libfontconfig1-dev))
-DEB_LUA_FLAG := $(findstring ok installed,$(shell dpkg-query -W
-f='$${Status}' liblua5.2-dev))
+DEB_LUA_FLAG := $(findstring ok installed,$(shell dpkg-query -W
-f='$${Status}' liblua5.1-0-dev))
include /usr/share/dpkg/buildtools.mk
@@ -64,8 +64,8 @@
# Use lua if it is installed
ifneq (,$(DEB_LUA_FLAG))
-CONFINCS += `$(PKG_CONFIG) --cflags lua5.2`
-CONFLIBS += `$(PKG_CONFIG) --libs lua5.2`
+CONFINCS += `$(PKG_CONFIG) --cflags lua5.1`
+CONFLIBS += `$(PKG_CONFIG) --libs lua5.1`
CONFDEFS += -DUSE_LUA
CONFEXT_OBJS += LUAHandler.o
endif
