I will murder someone for this

.gitmodules

@@ -0,0 +1,12 @@
+[submodule "foreign/lua52"]
+	path = foreign/lua52
+	url = https://github.com/lua/lua
+	branch = v5-2
+[submodule "foreign/lua53"]
+	path = foreign/lua53
+	url = https://github.com/lua/lua
+	branch = v5.3
+[submodule "foreign/lua54"]
+	path = foreign/lua54
+	url = https://github.com/lua/lua
+	branch = v5.4

build.zig

@@ -24,6 +24,45 @@ fn addEngineSources(c: *std.Build.Step.Compile) void {
     });
 }
 
+const LuaVersion = enum {
+    lua52,
+    lua53,
+    lua54,
+};
+
+// For the test architecture, we specify the target Lua version we so desire.
+// This can be checked for with Lua's _VERSION
+
+fn compileTheRightLua(b: *std.Build, c: *std.Build.Step.Compile, version: LuaVersion) !void {
+    const alloc = b.allocator;
+    const dirName = @tagName(version);
+
+    const rootPath = try std.mem.join(alloc, std.fs.path.sep_str, &.{"foreign", dirName});
+
+    c.addIncludePath(b.path(rootPath));
+
+    // get all the .c files
+    var files = std.ArrayList([]const u8).init(alloc);
+    errdefer files.deinit();
+
+    var dir = try std.fs.cwd().openDir(rootPath, std.fs.Dir.OpenDirOptions {.iterate = true});
+    defer dir.close();
+
+    var iter = dir.iterate();
+
+    while(try iter.next()) |e| {
+        if(std.mem.startsWith(u8, e.name, "l") and std.mem.endsWith(u8, e.name, ".c") and !std.mem.eql(u8, e.name, "lua.c")) {
+            const name = try alloc.dupe(u8, e.name);
+            try files.append(name);
+        }
+    }
+
+    c.addCSourceFiles(.{
+        .root = b.path(rootPath),
+        .files = files.items,
+    });
+}
+
 pub fn build(b: *std.Build) void {
     const os = builtin.target.os.tag;
 
@@ -72,21 +111,19 @@ pub fn build(b: *std.Build) void {
     if (os == .windows) {
         // use the msvc win64 dll versions and copy them to raylib/ and lua/
         // get raylib from https://github.com/raysan5/raylib/releases
-        // get lua from https://luabinaries.sourceforge.net/
-        emulator.addIncludePath(b.path("lua/include"));
         emulator.addIncludePath(b.path("raylib/include"));
-        emulator.addObjectFile(b.path("lua/lua54.lib"));
         emulator.addObjectFile(b.path("raylib/lib/raylibdll.lib"));
     } else {
-        emulator.linkSystemLibrary("lua");
         emulator.linkSystemLibrary("raylib");
     }
+    const luaVer = b.option(LuaVersion, "lua", "The version of Lua to use.") orelse LuaVersion.lua54;
     emulator.addCSourceFiles(.{
         .files = &.{
             "src/testLuaArch.c",
             "src/emulator.c",
         },
     });
+    compileTheRightLua(b, emulator, luaVer) catch unreachable;
 
     // forces us to link in everything too
     emulator.linkLibrary(engineStatic);

foreign/lua52

@@ -0,0 +1 @@
+Subproject commit 4324904b60db5243ede68d0922c1bf3c0dd05986

foreign/lua53

@@ -0,0 +1 @@
+Subproject commit 75ea9ccbea7c4886f30da147fb67b693b2624c26

foreign/lua54

@@ -0,0 +1 @@
+Subproject commit 1b0f943da7dfb25987456a77259edbeea0b94edc

src/testLuaArch.c

@@ -3,10 +3,29 @@
 #include <lauxlib.h>
 #include <assert.h>
 #include <string.h>
+#include <math.h>
 #include "neonucleus.h"
 
 char *testLuaSandbox = NULL;
 
+#if LUA_VERSION_NUM == 502
+
+// monkey patching
+
+bool lua_isinteger(lua_State *L, int i) {
+    if(lua_type(L, i) != LUA_TNUMBER) return false;
+    double x = lua_tonumber(L, i);
+    if(isinf(x)) return false;
+    if(isnan(x)) return false;
+    return trunc(x) == x;
+}
+
+void lua_seti(lua_State *L, int arr, int i) {
+    lua_rawseti(L, arr, i);
+}
+
+#endif
+
 typedef struct testLuaArch {
     lua_State *L;
     nn_computer *computer;
@@ -55,12 +74,12 @@ static nn_value testLuaArch_getValue(lua_State *L, int index) {
         const char *s = lua_tolstring(L, index, &l);
         return nn_values_string(s, l);
     }
-    if(type == LUA_TNUMBER && lua_isnumber(L, index)) {
-        return nn_values_number(lua_tonumber(L, index));
-    }
     if(type == LUA_TNUMBER && lua_isinteger(L, index)) {
         return nn_values_integer(lua_tointeger(L, index));
     }
+    if(type == LUA_TNUMBER && lua_isnumber(L, index)) {
+        return nn_values_number(lua_tonumber(L, index));
+    }
     //TODO: bring it back once I make everything else not leak memory
     //luaL_argcheck(L, false, index, luaL_typename(L, index));
     return nn_values_nil();
@@ -628,7 +647,15 @@ void testLuaArch_teardown(nn_computer *computer, testLuaArch *arch, void *_) {
 
 void testLuaArch_tick(nn_computer *computer, testLuaArch *arch, void *_) {
     int ret = 0;
+#if LUA_VERSION_NUM == 504
     int res = lua_resume(arch->L, NULL, 0, &ret);
+#endif
+#if LUA_VERSION_NUM == 503
+    int res = lua_resume(arch->L, NULL, 0);
+#endif
+#if LUA_VERSION_NUM == 502
+    int res = lua_resume(arch->L, NULL, 0);
+#endif
     if(res == LUA_OK) {
         // machine halted, this is no good
         lua_pop(arch->L, ret);