qol: implement easier building and distribution

.gitignore

@@ -33,7 +33,10 @@
 *.app
 
 # Build
-build/
+/build/
+/build-debug/
+/build-release/
+/dist/
 build-gcc/
 compile_commands.json
 vcpkg_installed/

Makefile

@@ -0,0 +1,55 @@
+# kappa — build convenience Makefile
+#
+# Targets:
+#   build        — default build (build/)
+#   debug        — Debug build (build-debug/)
+#   release      - Release build (build-release/)
+#   dist         - tar.zst tarball of the release build (requires zstd)
+#   dist-clean   - remove everything under dist/
+#
+# Overridable: make release CXX=g++ GENERATOR="Unix Makefiles"
+
+CC        ?= clang
+CXX       ?= clang++
+GENERATOR ?= Ninja
+
+BUILD_DIR    ?= build
+DEBUG_DIR    ?= build-debug
+RELEASE_DIR  ?= build-release
+DIST_DIR     ?= dist
+
+GIT_COMMIT := $(shell git rev-parse --short HEAD 2>/dev/null || echo unknown)
+GIT_TAG    := $(shell git describe --tags --abbrev=0 2>/dev/null || echo 0.1.0)
+STAMP      := $(shell date +%Y-%M)
+DIST_NAME  := kappa-$(GIT_COMMIT)-$(GIT_TAG)-$(STAMP)
+
+CMAKE := cmake
+
+.PHONY: build debug release dist dist-clean
+
+build:
+	$(CMAKE) -S . -B $(BUILD_DIR) -G $(GENERATOR) \
+		-DCMAKE_C_COMPILER=$(CC) -DCMAKE_CXX_COMPILER=$(CXX)
+	$(CMAKE) --build $(BUILD_DIR)
+
+debug:
+	$(CMAKE) -S . -B $(DEBUG_DIR) -G $(GENERATOR) \
+		-DCMAKE_BUILD_TYPE=Debug \
+		-DCMAKE_C_COMPILER=$(CC) -DCMAKE_CXX_COMPILER=$(CXX)
+	$(CMAKE) --build $(DEBUG_DIR)
+
+release:
+	$(CMAKE) -S . -B $(RELEASE_DIR) -G $(GENERATOR) \
+		-DCMAKE_BUILD_TYPE=Release \
+		-DCMAKE_C_COMPILER=$(CC) -DCMAKE_CXX_COMPILER=$(CXX)
+	$(CMAKE) --build $(RELEASE_DIR)
+
+dist: release
+	rm -rf $(DIST_DIR)/$(DIST_NAME)
+	$(CMAKE) --install $(RELEASE_DIR) --prefix $(DIST_DIR)/$(DIST_NAME)
+	tar --zstd -cf $(DIST_DIR)/$(DIST_NAME).tar.zst -C $(DIST_DIR) $(DIST_NAME)
+	rm -rf $(DIST_DIR)/$(DIST_NAME)
+	@echo "dist: $(DIST_DIR)/$(DIST_NAME).tar.zst"
+
+dist-clean:
+	rm -rf $(DIST_DIR)

include/kappa/build/build.hpp

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "kappa/resolve/plan.hpp"
+
+#include <string>
+
+namespace kappa::build {
+
+struct BuildResult {
+    bool ok = false;
+    std::string phase;  // phase that failed, e.g. "prepare" or "build"
+    std::string error;
+};
+
+// Build a single package step into work_dir.
+//
+// NOTE: compile-only stub — the real build backend was never committed.
+// Always fails so the rebuild pipeline never records a fake install.
+BuildResult build(const resolve::BuildStep& step,
+                  const std::string& work_dir,
+                  int jobs);
+
+} // namespace kappa::build

src/build/build.cpp

@@ -0,0 +1,18 @@
+#include "kappa/build/build.hpp"
+
+#include <format>
+
+namespace kappa::build {
+
+BuildResult build(const resolve::BuildStep& step,
+                  const std::string& work_dir,
+                  int jobs) {
+    BuildResult result;
+    result.phase = "build";
+    result.error = std::format(
+        "build backend not implemented (stub): {} in {} (jobs={})",
+        step.name, work_dir, jobs);
+    return result;
+}
+
+} // namespace kappa::build