try fixing flake

Makefile

@@ -19,6 +19,11 @@ SDL_CFLAGS := $(shell pkg-config --cflags sdl3 sdl3-ttf sdl3-image)
 SDL_LIBS_DEBUG := $(shell pkg-config --libs sdl3 sdl3-ttf sdl3-image)
 SDL_LIBS_RELEASE := $(shell pkg-config --libs sdl3 sdl3-ttf sdl3-image)
 
+# ----------------- MRUBY --------------
+
+MRUBY_CFLAGS := -I$(MRUBY_INCLUDE)
+MRUBY_LIBS := $(MRUBY_LIB)
+
 # ---------------- FLAGS ----------------
 
 CFLAGS_DEBUG := \
@@ -26,25 +31,19 @@ CFLAGS_DEBUG := \
 	-Og -g -fno-omit-frame-pointer \
 	-Wno-unused-command-line-argument \
 	-I./include -I./libs/mruby/build/host/include \
-	$(SDL_CFLAGS)
+	$(SDL_CFLAGS) $(MRUBY_CFLAGS)
 
 CFLAGS_RELEASE := \
-	-std=c++20 -O3 -march=x86-64 -mtune=generic \
+	-std=c++20 -O3 -mtune=generic \
 	-flto=thin \
 	-fno-rtti -fomit-frame-pointer -DNDEBUG -s \
 	-Wno-unused-command-line-argument \
 	-I./include -I./libs/mruby/build/host/include \
-	$(SDL_CFLAGS)
+	$(SDL_CFLAGS) $(MRUBY_CFLAGS)
 
 PCH_CFLAGS_DEBUG := $(CFLAGS_DEBUG) -x c++-header
 PCH_CFLAGS_RELEASE := $(CFLAGS_RELEASE) -x c++-header
 
-# ---------------- LIBS ----------------
-
-LIBS := ./libs/mruby/build/host/lib/libmruby.a
-
-MGEM_DIR := ./libs/l_mgems
-
 # ---------------- SOURCES ----------------
 
 SRC := $(shell find $(SRC_DIR) -name "*.cc")
@@ -57,18 +56,18 @@ DEP_RELEASE := $(OBJ_RELEASE:.o=.d)
 
 # ---------------- TARGETS ----------------
 
-.PHONY: all debug release clean mgems
+.PHONY: all debug release clean scripts
 
 all: debug
 
-debug: mgems $(TARGET_DEBUG)
+debug: scripts $(TARGET_DEBUG)
 
-release: mgems $(TARGET_RELEASE)
+release: scripts $(TARGET_RELEASE)
 
 # ---------------- MRB_MGEMS ----------------
 
-mgems:
+scripts:
-	@$(MGEM_DIR)/compile.sh
+	./scripts/compile.sh
 
 # ---------------- PCH ----------------
 
@@ -86,12 +85,12 @@ $(PCH_RELEASE): $(INCLUDE_DIR)/pch.h
 
 $(TARGET_DEBUG): $(PCH_DEBUG) $(OBJ_DEBUG)
 	@mkdir -p $(BIN_DIR)
-	@$(CXX) $(CFLAGS_DEBUG) -o $@ $(OBJ_DEBUG) $(SDL_LIBS_DEBUG) $(LIBS)
+	@$(CXX) $(CFLAGS_DEBUG) -o $@ $(OBJ_DEBUG) $(SDL_LIBS_DEBUG) $(MRUBY_LIBS)
 	@echo "Debug build complete: $@"
 
 $(TARGET_RELEASE): $(PCH_RELEASE) $(OBJ_RELEASE)
 	@mkdir -p $(BIN_DIR)
-	@$(CXX) $(CFLAGS_RELEASE) -o $@ $(OBJ_RELEASE) $(SDL_LIBS_RELEASE) $(LIBS)
+	@$(CXX) $(CFLAGS_RELEASE) -o $@ $(OBJ_RELEASE) $(SDL_LIBS_RELEASE) $(MRUBY_LIBS)
 	@echo "Release build complete: $@"
 
 # ---------------- COMPILE ----------------
@@ -115,5 +114,5 @@ $(OBJ_DIR)/release/%.o: $(SRC_DIR)/%.cc $(PCH_RELEASE)
 
 clean:
 	@rm -rf $(OBJ_DIR) $(BIN_DIR)
-	@$(MGEM_DIR)/compile.sh clean
+	./compile.sh clean
 	@echo "Cleaned build artifacts."

flake.nix

@@ -3,48 +3,126 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    self.submodules = true;
   };
 
   outputs =
-    { self, nixpkgs }:
+    { nixpkgs, ... }:
     let
-      systems = [ "x86_64-linux" ];
+      system = "x86_64-linux";
+
+      pkgs = nixpkgs.legacyPackages.${system};
+      staticPkgs = pkgs.pkgsStatic;
+
+      mruby = staticPkgs.stdenv.mkDerivation {
+        pname = "mruby";
+        version = "0.0.1";
+
+        src = staticPkgs.lib.cleanSourceWith {
+          src = ./libs;
+          name = "mruby-src";
+        };
+
+        patches = [
+          ./libs/changes.patch
+        ];
+
+        nativeBuildInputs = with pkgs; [
+          ruby
+          gnumake
+          clang
+        ];
+
+        buildPhase = ''
+          cd mruby
+          rake
+        '';
+
+        installPhase = ''
+          mkdir -p $out
+
+          cp -r build/host/lib $out/lib
+          cp -r build/host/include $out/include
+
+          mkdir -p $out/bin
+          cp build/host/bin/mrbc $out/bin/mrbc
+        '';
+      };
+
+      game-engine = staticPkgs.stdenv.mkDerivation {
+        pname = "game-engine";
+        version = "0.1.0";
+
+        src = ./.;
+
+        nativeBuildInputs = with pkgs; [
+          clang
+          pkg-config
+          gnumake
+          bear
+          ccache
+          xxd
+        ];
+
+        buildInputs = [
+          pkgs.sdl3
+          pkgs.sdl3-ttf
+          pkgs.sdl3-image
+
+          mruby
+        ];
+
+        buildPhase = ''
+          make \
+            MRBC=${mruby}/bin/mrbc \
+            MRUBY_INCLUDE=${mruby}/include \
+            MRUBY_LIB=${mruby}/lib/libmruby.a
+        '';
+
+        installPhase = ''
+          mkdir -p $out/bin
+          cp game-engine $out/bin/game-engine
+        '';
+
+        CC = "${pkgs.clang}/bin/clang";
+        CXX = "${pkgs.clang}/bin/clang++";
+      };
 
-      forAllSystems =
-        f:
-        nixpkgs.lib.genAttrs systems (
-          system:
-          f (
-            import nixpkgs {
-              inherit system;
-            }
-          )
-        );
     in
     {
-      devShells = forAllSystems (pkgs: {
+      packages.${system} = {
-        default = pkgs.mkShell {
+        default = game-engine;
-          packages = with pkgs; [
+        game-engine = game-engine;
-            clang-tools
+        mruby = mruby;
-            clang
+      };
-            ccache
-            pkg-config
-            gnumake
-            ruby
-            xxd
-            bear
 
-            sdl3
+      devShells.${system}.default = pkgs.mkShell {
-            sdl3-ttf
+        inputsFrom = [ game-engine ];
-            sdl3-image
-          ];
 
-          shellHook = ''
+        packages = [
-            export CC=clang
+          pkgs.clang-tools
-            export CXX=clang++
+          pkgs.clang
-            export LD=clang
+          pkgs.ccache
-          '';
+          pkgs.pkg-config
-        };
+          pkgs.gnumake
-      });
+          pkgs.bear
+          pkgs.ruby
+          pkgs.xxd
+
+          pkgs.sdl3
+          pkgs.sdl3-ttf
+          pkgs.sdl3-image
+        ];
+
+        shellHook = ''
+          export CC=clang
+          export CXX=clang++
+          export LD=clang
+
+          export MRBC=${mruby}/bin/mrbc
+          export MRUBY_INCLUDE=${mruby}/include
+          export MRUBY_LIB=${mruby}/lib/libmruby.a
+        '';
+      };
     };
 }

libs/changes.patch

@@ -0,0 +1,30 @@
+--- ./mruby/build_config/default.rb
++++ ./mruby/build_config/default.rb
+@@ -1,6 +1,18 @@
+ MRuby::Build.new do |conf|
+   # load specific toolchain settings
+-  conf.toolchain
++  conf.toolchain :gcc
++
++  conf.cc do |cc|
++    cc.command = ENV['CC']
++  end
++
++  conf.cxx do |cxx|
++    cxx.command = ENV['CXX']
++  end
++
++  conf.linker do |linker|
++    linker.command = ENV['CXX']
++  end
+ 
+   # Use mrbgems
+   # conf.gem 'examples/mrbgems/ruby_extension_example'
+@@ -79,5 +79,5 @@
+   # Turn on `enable_debug` for better debugging
+   # conf.enable_debug
+-  conf.enable_bintest
+-  conf.enable_test
++  # conf.enable_bintest
++  # conf.enable_test
+ end

scripts/compile.sh

@@ -4,7 +4,7 @@ set -e
 
 SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
 OUTPUT_TMP=$(mktemp)
-OUTPUT="$SCRIPT_DIR/../../include/bindings/ruby_compiled.h"
+OUTPUT="$SCRIPT_DIR/../include/bindings/ruby_compiled.h"
 
 if test "$1" = "clean"; then
   rm -f "$OUTPUT"
@@ -28,7 +28,7 @@ fi
 
 echo "Compiling mgems..."
 
-"$SCRIPT_DIR/../mruby/bin/mrbc" -o "$OUTPUT_TMP" "${FILES[@]}"
+"${MRBC:-mrbc}" -o "$OUTPUT_TMP" "${FILES[@]}"
 
 {
   echo "#ifndef MGEMS_H"