comma

- 4 tests for kappa bump: version update, version written to file,
  source URL preserved, requires version arg
- 3 tests for kappa bump-all: finds newer version, reports count,
  requires directory arg

Total: 103 → 110 in test-full.sh (30+23+110 = 163 overall)

.clang-tidy

@@ -6,6 +6,7 @@ Checks: >
   portability-*,
   readability-*,
   -modernize-use-trailing-return-type,
+  -portability-avoid-pragma-once,
   -readability-identifier-length,
   -readability-magic-numbers,
   -readability-identifier-naming

.gitea/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+    container: archlinux:latest
+    steps:
+      - name: Install dependencies
+        run: |
+          pacman -Syu --noconfirm
+          pacman -S --noconfirm clang cmake ninja git
+
+      - name: Checkout
+        run: |
+          git clone --depth 1 "$GITHUB_SERVER_URL/$GITHUB_REPOSITORY" .
+          git fetch origin "$GITHUB_REF"
+          git checkout FETCH_HEAD
+
+      - name: Build kappa
+        run: |
+          cmake -B build -G Ninja \
+            -DCMAKE_C_COMPILER=clang \
+            -DCMAKE_CXX_COMPILER=clang++
+          cmake --build build
+
+      - name: DSL and CLI tests
+        run: ./test.sh
+
+      - name: Init-switching tests
+        run: ./test-init-switch.sh
+
+      - name: Comprehensive tests
+        run: ./test-full.sh

.gitignore

@@ -33,8 +33,17 @@
 *.app
 
 # Build
-build/
+/build/
+/build-debug/
+/build-release/
+/dist/
+build-gcc/
 compile_commands.json
 vcpkg_installed/
-kappa
+/kappa
+
+# Agent session state
+.omo/
+.logs/
+.opencode/
 

CMakeLists.txt

@@ -1,11 +1,9 @@
 cmake_minimum_required(VERSION 3.20)
 
-# Enforce Clang
-set(CMAKE_C_COMPILER clang)
-set(CMAKE_CXX_COMPILER clang++)
-
 project(kappa VERSION 0.1.0 LANGUAGES CXX)
 
+find_package(Threads REQUIRED)
+
 set(CMAKE_CXX_STANDARD 23)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -53,3 +51,7 @@ add_executable(kappa
   src/system/activate.cpp
 )
 target_include_directories(kappa PRIVATE include)
+target_link_libraries(kappa PRIVATE Threads::Threads)
+target_compile_options(kappa PRIVATE -Wall -Wextra -Wpedantic)
+
+install(TARGETS kappa RUNTIME DESTINATION bin)

CONTRIBUTING.md

@@ -8,9 +8,9 @@ project, keep reading.
 
 These aren't guidelines. They're the deal.
 
-### 1. C++23 or don't bother
+### 1. C++23, or don't bother
 
-We compile with Clang, `-std=c++23`, and `-Werror`. If your code needs a
+We compile with Clang, `-std=c++23`, and zero warnings. If your code needs a
 polyfill for `std::format` or can't handle designated initializers, it
 doesn't belong here. The standard library is your only dependency. Zero
 external C++ libraries. Not even Boost.
@@ -63,17 +63,20 @@ lock. `std::mutex`, `std::atomic`, `std::condition_variable` — use them
 correctly or don't use them at all. If you don't know what `memory_order`
 means, stay out of the scheduler.
 
-### 6. Tests are shell scripts. For now.
+### 6. Tests are shell scripts.
 
-Integration tests live in `test.sh` and `test-init-switch.sh`. They
-exercise the CLI. If you add a subcommand, add a test. C++ unit tests
-are welcome — set up Google Test or Catch2 in CMake and we'll merge it.
+Integration tests live in three suites. If you add a subcommand, add a test.
 
 ```sh
-./test.sh               # 31 tests, must pass
-./test-init-switch.sh   # 23 tests, must pass
+./test.sh               # 30 tests — DSL parsing, config, services, init systems
+./test-init-switch.sh   # 23 tests — init-switching, rebuild impact, bootloaders
+./test-full.sh          # 85 tests — CLI, all keywords, repos, add/remove,
+                        #   resolver conflicts, deptrees, build, env ops,
+                        #   index generation, --root, imports, doctor, and more
 ```
 
+All three must pass. CI enforces this on every push to `main`.
+
 ### 7. Backward compatibility is mandatory
 
 The `.kap` DSL is the contract. You can add keywords. You cannot remove
@@ -85,29 +88,34 @@ change means someone's `config.kap` stops parsing, it doesn't ship.
 ### Pick something
 
 Good first issues:
-- Adding a 6th init system backend
-- Adding a 3rd bootloader backend
-- C++ unit test framework setup
-- Shell completion scripts
+
+- Adding a 6th init system backend (we have 5: systemd, openrc, s6, runit, dinit)
+- Adding a 3rd bootloader backend (we have 2: grub, limine)
+- Improving the `kappa doctor` diagnostics for package recipes
+- Adding `--features` / `--config` flags to `kappa add`
+- Shell completion scripts (bash, zsh, fish)
 
 Ambitious issues:
+
 - Binary package support (pre-built caches)
 - Remote build farm (distcc-style)
-- Signed package verification
+- Signed package verification with index signing
 - Filesystem overlay activation (like Nix profiles)
+- Transitive dependency resolution (auto-including deps not in config)
 
 ### Send a PR
 
 1. Fork the repo
 2. Create a branch: `feat/my-thing` or `fix/my-bug`
 3. Write code that follows the rules above
-4. Run `./test.sh && ./test-init-switch.sh` — both must pass
+4. Run `./test.sh && ./test-init-switch.sh && ./test-full.sh` — all three must pass
 5. Open a PR against `main`
 
 ### PR requirements
 
-- Build must pass: `cmake --build build` with zero warnings
-- Tests must pass: both shell test suites
+- Build must pass: `cmake --build build` with zero warnings on Clang 17+
+- Tests must pass: all three shell test suites
+- Follow the conventions in [STYLEGUIDE.md](STYLEGUIDE.md)
 - No commented-out code. No dead code. No TODO without a date.
 - Commit messages in imperative: `Add runit backend` not `Added runit backend`
 

Makefile

@@ -0,0 +1,72 @@
+# 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)
+#   test         — build then run all three test suites
+#   clean        - remove all build directories
+#   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 test clean 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)
+
+test: build
+	@echo "==> test.sh"
+	@./test.sh
+	@echo ""
+	@echo "==> test-init-switch.sh"
+	@./test-init-switch.sh
+	@echo ""
+	@echo "==> test-full.sh"
+	@./test-full.sh
+	@echo ""
+	@echo "all test suites passed"
+
+clean:
+	rm -rf $(BUILD_DIR) $(DEBUG_DIR) $(RELEASE_DIR)

README.md

@@ -72,15 +72,45 @@ kappa rebuild config.kap   # boot.init = "openrc" — only 5 packages actually r
   simultaneously, eight jobs each. The scheduler uses depth-based priority
   grouping so leaf dependencies unblock as much work as possible first.
 
-- **Package recipe caching.** Declare `remotes = ["https://repo.example.com/"]`
-  in your config. Kappa fetches `.kap` files on demand, caches them, and only
-  re-fetches when the remote version is newer.
+- **Package recipe caching with indexed repos.** Declare named repos with
+  channels and mirrors in your config. Kappa fetches `index.kap` from each
+  repo, caches it, and only re-fetches when the remote changes. Package recipes
+  are resolved from the index — fast, offline-tolerant, and mirror-aware.
 
-- **Source tarball caching.** Downloaded once, stored at `/kappa/cache/`.
-  Rebuilds don't touch the network unless versions change.
+```kap
+repos {
+    kappa-os {
+        url      = "https://packages.kappa-os.org/"
+        channels = ["stable"]
+        mirrors  = [
+            "https://cdn.kappa-os.org/",
+            "https://eu.kappa-os.org/",
+        ]
+    }
+}
+```
+
+`remotes = [...]` still works. Repos are tried first, then legacy remotes.
+
+- **Source tarball caching.** Downloaded once, stored at `$KAPPA_ROOT/cache/`
+  (default: `/usr/local/kappa/cache/`). Rebuilds don't touch the network
+  unless versions change.
+
+- **Env operators.** Three ways to set build environment variables:
+  `=` (hard set), `+=` (append with space), `?=` (soft set — only if not
+  already defined). System-level env propagates to all packages.
+
+```kap
+env {
+    CFLAGS  = "-O2 -march=native"    # overwrite
+    CFLAGS += "-pipe"                # append → "-O2 -march=native -pipe"
+    CFLAGS ?= "-g"                   # soft — only if not set
+}
+```
 
 - **Conflicts.** `systemd` declares `conflicts = ["eudev", "elogind"]`. The
-  resolver catches mutual incompatibility before a build starts.
+  resolver catches mutual incompatibility before a build starts — and now
+  actually reports it, rather than silently ignoring it.
 
 - **Init-agnostic system config.** `groups { wheel { gid = 998 } }` — kappa
   creates the groups. `system { hostname = "mybox" }` — kappa writes
@@ -103,46 +133,62 @@ kappa rebuild config.kap   # boot.init = "openrc" — only 5 packages actually r
 
 ### Quick start
 
+> **Note for 0.1.x users**: The default store root has moved from `/kappa` to
+> `/usr/local/kappa` (FHS 3.0). Set `KAPPA_ROOT` to your existing `/kappa`
+> directory to keep using the old location.
+
 ```sh
 # Build kappa (needs Clang 17+, CMake 3.20+, C++23)
 cmake -B build -G Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
 cmake --build build
 
-# Write a config
-cat > system.kap << 'EOF'
-system { hostname = "kappa.local" }
-packages { nginx {} }
-services { nginx { enable = true } }
-boot {
-    kernel = "linux"; init = "s6"; root = "/dev/sda1"; bootloader = "limine"
-}
-users { root { shell = "/bin/zsh" } }
-remotes = ["https://packages.kappa-os.org/stable/"]
-EOF
+# Add packages to your system config
+build/kappa add make
+build/kappa add nginx ">=1.24"
+build/kappa add zlib
 
-# Parse it
-build/kappa parse-config system.kap
+# Rebuild — kappa fetches recipes, resolves deps, builds everything
+build/kappa rebuild $KAPPA_ROOT/system/config.kap
 
-# Rebuild
-build/kappa rebuild system.kap
+# Remove packages
+build/kappa remove zlib
 ```
 
+No config files to write by hand. `kappa add` writes the `packages {}` block
+for you. `kappa rebuild` handles the rest.
+
 ### Subcommands
 
 | Command | What it does |
 |---------|-------------|
-| `parse-package <file>` | Validate a `.kap` package definition |
-| `parse-config <file>` | Validate a system configuration |
-| `validate <file>` | Validate any kappa file |
-| `format <file>` | Pretty-print to canonical style |
-| `doctor <file>` | Check for issues and warnings |
-| `resolve <config>` | Compute a build plan |
+| `add <pkg> [version]` | Add a package to system config |
+| `remove <pkg>` | Remove a package from system config |
+| `build <package>` | Build a single package from its `.kap` definition |
+| `rebuild <config>` | Diff config against installed state, rebuild changed |
+| `resolve <config>` | Compute a build plan (shows order, deps, conflicts) |
+| `doctor <file>` | Check a file for issues and warnings |
 | `fetch <package>` | Download and verify source tarballs |
 | `fetch-package <name>` | Fetch a package recipe from remotes |
-| `build <package>` | Build a single package |
-| `rebuild <config>` | Diff config against installed state, rebuild changed |
+| `format <file>` | Pretty-print to canonical style |
+| `index <dir>` | Build an `index.kap` from `.kap` files in a directory |
 | `list` | Show installed packages |
+| `parse-config <file>` | Validate a system configuration |
+| `parse-package <file>` | Validate a `.kap` package definition |
 | `rollback` | Show available generations |
+| `validate <file>` | Validate any kappa file (package, config, or index) |
+
+### Repo maintenance
+
+```sh
+# Generate an index from a directory of .kap files
+kappa index ./packages/
+# → packages/index.kap
+
+# Host the directory behind any HTTP server. That's your repo.
+```
+
+The index is a tiny text file listing every package and version.
+Clients fetch it once, cache it, and check for updates via HTTP headers.
 
 ### License
 
@@ -151,4 +197,7 @@ BSD 2-Clause. Do whatever you want. Just don't sue us.
 ### Contributing
 
 See [CONTRIBUTING.md](CONTRIBUTING.md). We're opinionated but we merge good
-code.
+code. See [STYLEGUIDE.md](STYLEGUIDE.md) for code conventions.
+
+Tests: 138 integration tests across three suites. CI runs on Arch Linux.
+Everything passes or nothing merges.

STYLEGUIDE.md

@@ -0,0 +1,484 @@
+# Style Guide
+
+If you're reading this because you thought kappa's C++ looked different from
+what you're used to — good. That's the point.
+
+This isn't a suggestion box. It's what the codebase looks like, and it's what
+your code will look like after you've rewritten it three times because the PR
+reviewer sent it back. Save yourself the rewrite. Read this first.
+
+---
+
+## The Philosophy
+
+We write C++ like it's the year 2026 and the committee finally shipped
+something usable. No polyfills. No third-party libraries. No Boost. The
+standard library is sufficient for a package manager. If you disagree, you
+haven't read `<format>` closely enough.
+
+Every line of kappa assumes the reader is competent. We don't explain what
+`std::string_view` is. We don't annotate obvious control flow. Comments exist
+to explain *why*, never *what*. If your code needs a comment to be
+understood, the code is wrong.
+
+Simplicity is a moral position. The scheduler is the hardest thing in this
+codebase, and it's 290 lines. If your feature adds more than that, you're
+building the wrong feature.
+
+---
+
+## Naming
+
+### Structs, classes, enums
+
+```cpp
+// PascalCase. Always.
+struct BuildResult { };
+enum class TokenType : std::uint8_t { };
+
+// Enum values are PascalCase too. This isn't Java.
+enum class EnvMode : std::uint8_t { Set, Soft, Append };
+
+// Acronyms stay capitalized. B-Tree is BTree, not Btree.
+// Two-letter acronyms stay capitalized. ID, not Id.
+```
+
+Type names state what the thing *is*, not what it's *for*. `SchedResult`, not
+`ResultForScheduler`. `InitPaths`, not `PathsForInitSystems`.
+
+### Variables and functions
+
+```cpp
+// snake_case. No Hungarian notation. No m_ prefix. No s_ prefix.
+int pending_deps = 0;
+void compute_depths(Scheduler& s);
+std::string_view token_name(TokenType type);
+```
+
+Member variables and locals look identical. If you can't tell them apart,
+your functions are too long. Fix the function.
+
+### Files
+
+```
+src/service/openrc.cpp          # snake_case, lowercase
+include/kappa/service/types.hpp # .hpp for headers, .cpp for source
+```
+
+One public class per header is a myth invented by Java developers. Group
+related declarations. `types.hpp` holds all enums and structs for a module.
+If a module has one public struct and one public function, they go in the
+same header.
+
+---
+
+## Formatting
+
+### Indentation and braces
+
+Four spaces. Attached braces (a K&R variant). 
+
+```cpp
+// ✓ yes — brace on the same line as the control structure
+if (pid < 0) {
+    return -1;
+}
+
+// ✗ no — Allman/BSD braces on their own line
+if (pid < 0)
+{
+    return -1;
+}
+
+// ✗ no — missing braces on single-statement bodies
+if (pid < 0) return -1;
+```
+
+Always braces. Even for single statements. The compiler doesn't care.
+The human reviewing your diff at 2 AM does. clang-tidy will flag bare
+bodies — apply the fix every time.
+
+### Line length
+
+100 columns. Not 80 — we're not teletypes. Not 120 — if you need 120
+characters to express a thought, your thought is too complicated. Split it.
+
+### Section separators
+
+```cpp
+// --- Section description ---
+// or
+// ---------------------------------------------------------------------------
+// Longer section description spanning the full runway
+// ---------------------------------------------------------------------------
+```
+
+Thin lines (`---`) for sub-sections within a file. Thick lines
+(`-----------`) for top-level section boundaries. The difference communicates
+hierarchy without nesting.
+
+### Switch cases
+
+```cpp
+switch (is) {
+case InitSystem::Systemd:
+    return generate_systemd_service(spec);
+case InitSystem::S6:
+    return generate_s6_service(spec);
+case InitSystem::Unknown:
+default:
+    return {};
+}
+```
+
+Cases at the same indentation as the switch. No blocks around single-return
+cases. Break or return in every non-fallthrough case. If you're falling
+through intentionally, wrap it with `[[fallthrough]];` on a line by itself.
+
+---
+
+## Types
+
+### Use `auto` when the type is obvious, explicit when it isn't
+
+```cpp
+// ✓ yes — type is obvious from initialization
+auto scope = eval::make_default_scope();
+auto& pkg = registry.at(name);
+
+// ✓ yes — structured bindings, type is obvious
+for (auto& [key, val] : features) { }
+
+// ✓ yes — explicit where the type carries meaning
+std::unique_lock lock(s.mtx);  // not auto lock = ...
+std::uint64_t h = 14695981039346656037ULL; // not auto h = ...
+```
+
+### `const` is the default
+
+Everything is `const` until proven mutable.
+
+```cpp
+// ✓ yes
+const auto& step = plan.steps[i];
+for (const auto& entry : entries) { }
+
+// ✗ no — mutable when it shouldn't be
+auto& step = plan.steps[i];
+```
+
+### View types over owning types in parameters
+
+```cpp
+// ✓ yes
+void set_root(std::string_view path);
+bool is_supported(std::string_view name);
+
+// ✗ no
+void set_root(const std::string& path);
+```
+
+Return owning types. Accept views. The caller decides ownership. You decide
+what you need to read.
+
+### Strong enums only
+
+```cpp
+// ✓ yes
+enum class InitSystem : std::uint8_t { Systemd, OpenRC, S6 };
+
+// ✗ no
+enum InitSystem { INIT_SYSTEMD, INIT_OPENRC, INIT_S6 };
+```
+
+No unscoped enums. No ALL_CAPS enum values. No integer conversions without
+explicit intent. If you need to serialize an enum to an integer, write a
+`to_string` function. The enum's numeric value is an implementation detail,
+not an interface.
+
+---
+
+## Functions
+
+### One responsibility per function
+
+If your function name contains the word "and", it does at least two things
+and needs to be split. If the body doesn't fit on one screen, it does too
+much. "One screen" means approximately 30 lines. The scheduler's
+`compute_depths` is 30 lines. So is the resolver's `resolve`. They're at the
+upper bound. If yours is longer, you're doing something wrong.
+
+### Error handling: return, don't throw
+
+```cpp
+// ✓ yes
+struct FetchResult {
+    std::filesystem::path work_dir;
+    std::string error;
+    bool ok() const { return error.empty(); }
+};
+
+FetchResult fetch(const PackageDef& pkg);
+
+// ✗ no
+void fetch(const PackageDef& pkg); // throws on error
+```
+
+Exceptions are for unrecoverable programmer errors — out-of-memory, null
+dereference, violated invariants. They belong in constructors and in the
+parser (where `ParseError` is the only way to unwind back to diagnostics).
+
+Every operational failure — network down, disk full, configure script failed,
+hash mismatch — is a return value. A struct with `bool ok` and
+`std::string error`. Check the `ok` field, read the `error` string, don't
+catch exceptions for normal operation.
+
+### Return early, return often
+
+```cpp
+// ✓ yes
+if (to.empty()) {
+    return {false, "destination is empty"};
+}
+// ... main logic ...
+
+// ✗ no
+if (!to.empty()) {
+    // ... 40 lines of nesting ...
+} else {
+    return {false, "destination is empty"};
+}
+```
+
+Guard clauses at the top. Happy path straight down the left margin. If your
+code has three levels of nesting, you missed an early return opportunity.
+
+### Static helpers over lambdas
+
+If a helper is more than 5 lines, extract it to a file-static function above
+the public API. Named functions are greppable. Named functions show up in
+stack traces. Lambdas don't. The one exception is a `run_phase` lambda in
+`build()` — it captures local state that would require a 5-parameter helper
+and it's clearly a one-off control flow wrapper, not a reusable abstraction.
+
+---
+
+## Namespaces
+
+```cpp
+namespace kappa::module {
+
+// Everything goes here.
+
+} // namespace kappa::module
+```
+
+C++17 nested namespace syntax. Closing brace gets a comment with the
+namespace name. These comments survive diffs, refactors, and editors that
+collapse braces. They cost one line and save ten minutes of scrolling up to
+figure out which brace closes what.
+
+### No `using namespace` at file scope
+
+```cpp
+// ✓ yes — inside a function
+namespace fs = std::filesystem;
+
+// ✗ no — at file scope
+using namespace std;
+```
+
+Namespace aliases are acceptable inside functions — `namespace fs =
+std::filesystem;` is fine when the file does a lot of path manipulation. But
+at file scope? No. You're not writing `using namespace std;` at the top of a
+header and you're not doing the subtler version of the same sin.
+
+---
+
+## Headers
+
+```cpp
+#pragma once
+
+#include "kappa/resolve/plan.hpp"
+#include "kappa/dsl/ast.hpp"
+
+#include <string>
+#include <vector>
+
+namespace kappa::build {
+
+struct BuildResult { };
+
+BuildResult build(const resolve::BuildStep& step,
+                  const std::string& work_dir,
+                  int jobs);
+
+} // namespace kappa::build
+```
+
+`#pragma once` at the top. No include guards. This is 2026.
+
+Project headers first, in quotes. System headers second, in angle brackets.
+Blank line between the two groups. Alphabetical within each group.
+
+Headers include only what they need to compile. If `build.hpp` uses
+`resolve::BuildStep` by reference, it includes `resolve/plan.hpp`. It does
+not forward-declare `BuildStep` — we don't forward-declare across module
+boundaries. The include is the contract: "this module depends on that one."
+
+Headers never contain implementation. No `inline` functions. No
+template definitions in headers (we don't use templates). The one exception
+is `parse_util.hpp`, which defines `ParseError` inline because it's a thin
+exception wrapper and splitting it would be ceremony for ceremony's sake.
+One exception per codebase is a pattern. Two is a problem.
+
+---
+
+## Modules
+
+Every module follows this structure:
+
+```
+include/kappa/{module}/
+├── types.hpp       # enums, structs, parse/validate declarations
+├── {feature}.hpp   # public function declarations
+
+src/{module}/
+├── types.cpp       # parse/validate/describe implementations
+├── backend_a.cpp   # per-variant generation (if applicable)
+├── backend_b.cpp
+└── install.cpp     # dispatch + orchestration (if applicable)
+```
+
+If a module doesn't need `types.hpp` (single struct, single function), both
+go in `{feature}.hpp`. If a module has no backends, skip them. But don't
+invent a third pattern. `service/` and `boot/` are the templates. Copy them.
+
+---
+
+## Strings and formatting
+
+```cpp
+// ✓ yes
+auto msg = std::format("building {} (depth={})", name, depth);
+result.error = std::format("command exited with code {}: {}", rc, cmd);
+
+// ✗ no — ostringstream for trivial concatenation
+std::ostringstream oss;
+oss << "building " << name << " (depth=" << depth << ")";
+
+// ✓ yes — ostringstream for incremental construction
+std::ostringstream out;
+out << "[Unit]\n";
+out << std::format("Description={}\n", desc);
+```
+
+`std::format` for one-shot strings. `std::ostringstream` for building up
+output incrementally (service files, bootloader configs, formatter output).
+String concatenation with `+` is acceptable for two or three pieces.
+Anything more goes through `std::format`.
+
+### String views for parameters
+
+```cpp
+// ✓ yes
+InitSystem parse_init_system(std::string_view name);
+void print_error(std::ostream& os, std::string_view source,
+                 SourceLocation loc, std::string_view message);
+
+// ✗ no
+InitSystem parse_init_system(const std::string& name);
+```
+
+Views everywhere, except when you need to store the string.
+
+---
+
+## The DSL
+
+The `.kap` DSL grammar is the contract. You can extend it. You cannot break
+existing configs. Every new token type requires:
+1. An entry in `TokenType`
+2. A case in `token_name()`
+3. Parsing logic in the appropriate parser
+4. A formatting case in `format.cpp`
+5. At least one test in `test.sh` that exercises the new syntax
+
+If you're adding a keyword, think twice. The lexer already has 29 token
+types. Every new one increases parse time and mental overhead. Can this be
+expressed with the existing grammar? If yes, don't add a keyword.
+
+---
+
+## Thread safety
+
+The scheduler is multithreaded. If you touch shared state, you own the lock.
+
+```cpp
+{
+    std::unique_lock lock(s.mtx);
+    s.waiting.erase(idx);
+}
+// lock released here — no shared state access beyond this point
+```
+
+Use scoped locks. Never lock/unlock manually. Never hold a lock across a
+condition variable wait without understanding why. If you think you need
+`memory_order_release`, you probably need `memory_order_acq_rel` and you
+should document why in a three-line comment above the operation.
+
+If a data structure is touched by multiple threads, its access pattern must
+be documented at the declaration site, not in a PR description. "This is
+only written under the lock, read atomically elsewhere" goes in the header.
+
+---
+
+## What clang-tidy enforces
+
+We run with `-Wall -Wextra -Wpedantic` and a `.clang-tidy` config. Zero
+warnings. Not "zero warnings except for that one file." Zero.
+
+The following are non-negotiable:
+- Every `if`/`for`/`while` body has braces
+- `auto` variables that are never modified are `const auto`
+- Variables are initialized at declaration
+- No unused includes
+- No redundant declarations
+
+If clang-tidy suggests a fix and you disagree, you're wrong. Apply the fix.
+The only acceptable override is `// NOLINT` with a justification comment —
+and if you write that more than twice in a file, the reviewer will ask you to
+rethink your design.
+
+---
+
+## What we reject
+
+- **Comments that narrate the code.** `// Increment counter` above `i++`
+  is an insult. Delete it.
+
+- **Dead code.** No commented-out blocks. No `#if 0`. If it's not used,
+  it doesn't exist. Git remembers.
+
+- **Premature abstraction.** Three identical lines do not need a
+  function. Ten do. The threshold is somewhere in between and you should
+  err on the side of duplication.
+
+- **C heritage.** `printf`, `malloc`, `NULL`, raw `char*` strings,
+  `#define` constants. The 1970s called. Don't answer.
+
+- **Over-engineering.** The build backend doesn't need a plugin
+  architecture. The lexer doesn't need a state machine framework.
+  Solve the problem in front of you, not the one you imagine someone
+  might have in three years.
+
+- **Cleverness.** If your solution makes you feel smart, it's wrong.
+  The best code is the code you forget about because it never breaks.
+
+---
+
+Kappa does one thing: build your system from source, init-agnostically.
+Everything in this style guide exists to keep that codebase small, fast, and
+comprehensible. If a rule conflicts with that goal, the goal wins — but
+you'd better have a good reason, and you'd better write it down.

examples/builds/foo.kap

@@ -1,6 +1,6 @@
 /*
  * Per-package override for foo.
- * Lives at /kappa/system/builds/foo.kap
+ * Lives at /usr/local/kappa/system/builds/foo.kap
  *
  * Uses system config syntax — only features/config need to be specified.
  * The rest inherits from the package definition and system config.

examples/config.kap

@@ -1,6 +1,6 @@
 /*
  * Kappa system configuration.
- * Lives at /kappa/system/config.kap
+ * Lives at /usr/local/kappa/system/config.kap
  *
  * INIT SYSTEM SELECTION
  * =====================
@@ -67,6 +67,8 @@ system {
 
     env {
         CFLAGS    = "-O2 -march=native"
+        // packages inherit this appended flag
+        CFLAGS   += "-pipe"
         LDFLAGS   = "-Wl,--as-needed"
         MAKEFLAGS = "-j8"
     }
@@ -101,7 +103,7 @@ packages {
 
     /*
     // Per-package overrides can also live in
-    // /kappa/system/builds/<name>.kap
+    // /usr/local/kappa/system/builds/<name>.kap
     */
 }
 

examples/foo.kap

@@ -46,6 +46,17 @@
  *
  * The backend generators handle all translation.  Package authors only
  * need to pick the semantic type that describes their daemon's behaviour.
+ *
+ *
+ * ENV OPERATORS
+ * =============
+ *   key = "val"     hard set — overwrites any existing value
+ *   key ?= "val"    soft set — only applied if key is not already set
+ *   key += "val"    append   — adds to existing value with a space separator
+ *
+ * Order matters.  Subsequent entries in the same env block can append to
+ * earlier ones.  System-level env (from config.kap) is applied before
+ * package env, so packages can += to flags set globally.
  */
 package "foo" {
     const version = "1.2.3"
@@ -101,8 +112,12 @@ package "foo" {
     }
 
     env {
+        // hard set — overwrites any existing CFLAGS
         CFLAGS   = "-O2 -march=native"
+        // append  — now CFLAGS is "-O2 -march=native -pipe"
+        CFLAGS  += "-pipe"
         LDFLAGS  = "-Wl,--as-needed"
+        // soft set — only added if CFLAGS isn't already defined
         CFLAGS  ?= "-g"
     }
 

examples/index.kap

@@ -0,0 +1,5 @@
+index "local" {
+    foo { version = "1.2.3" }
+    postgresql { version = "16.3" }
+    make { version = "4.4.1" }
+}

examples/make.kap

@@ -0,0 +1,38 @@
+/*
+ * GNU Make — the build tool that builds everything else.
+ *
+ * This is the quintessential autotools package: ./configure, make, make install.
+ * If kappa can build this, it can build anything downstream.
+ *
+ * INIT-AGNOSTIC
+ * =============
+ * Make itself doesn't care about init systems — no service definitions,
+ * no boot requirements.  It's a pure build tool.
+ */
+package "make" {
+    const version = "4.4.1"
+    const source  = "https://ftp.gnu.org/gnu/make/make-${version}.tar.gz"
+    sha256 = "dd16fb1d67bfab79a72f5e8390735c49e3e8e70b4945a15ab1f81ddb78658fb3"
+    license = "GPL-3.0-or-later"
+
+    provides = ["make", "gmake"]
+
+    env {
+        CFLAGS  = "-O2"
+        CFLAGS += "-Wno-error"
+    }
+
+    build {
+        touch aclocal.m4 configure Makefile.in */Makefile.in
+        ./configure --prefix=${prefix}
+        make -j${jobs}
+    }
+
+    check {
+        make check
+    }
+
+    install {
+        make DESTDIR=${destdir} install
+    }
+}

examples/postgres.kap

@@ -77,6 +77,8 @@ package "postgresql" {
 
     env {
         CFLAGS  = "-O2"
+        // append security hardening flags
+        CFLAGS += "-D_FORTIFY_SOURCE=2"
         LDFLAGS = "-Wl,--as-needed"
     }
 

include/kappa/boot/bootloader.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <string>
+#include <string_view>
+
+#include "kappa/boot/types.hpp"
+
+namespace kappa::boot {
+
+struct BootSpec {
+    std::string kernel_path;   // e.g. "/kappa/boot/kernel"
+    std::string init_path;     // e.g. "/kappa/boot/init" (the symlink, stable across init swaps)
+    std::string root;          // e.g. "/dev/sda1" or "PARTUUID=xxx"
+    std::string kernel_params; // extra kernel cmdline params
+    std::string init_prev;     // previous init symlink for fallback entry; empty = no fallback
+};
+
+std::string generate_bootloader_config(Bootloader bl, const BootSpec& spec);
+std::string generate_limine_config(const BootSpec& spec);
+std::string generate_grub_config(const BootSpec& spec);
+
+struct BootloaderInstallResult {
+    bool ok;
+    std::string path;
+    std::string error;
+};
+
+BootloaderInstallResult install_bootloader_config(Bootloader bl,
+                                                  const BootSpec& spec,
+                                                  std::string_view prefix = "/");
+
+} // namespace kappa::boot

include/kappa/boot/types.hpp

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace kappa::boot {
+
+enum class Bootloader : std::uint8_t {
+    Grub,
+    Limine,
+    Unknown
+};
+
+Bootloader parse_bootloader(std::string_view name);
+
+std::string_view to_string(Bootloader bl);
+
+bool is_supported(std::string_view name);
+
+std::vector<Bootloader> all_bootloaders();
+
+std::string_view bootloader_description(Bootloader bl);
+
+struct BootloaderPaths {
+    std::string config_path;
+    std::string install_cmd;
+};
+
+BootloaderPaths bootloader_paths(Bootloader bl, std::string_view prefix = "/");
+
+} // namespace kappa::boot

include/kappa/build/build.hpp

@@ -0,0 +1,22 @@
+#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.
+// Runs prepare, build, check, and install phases in order,
+// with full variable interpolation and config file generation.
+BuildResult build(const resolve::BuildStep& step,
+                  const std::string& work_dir,
+                  int jobs);
+
+} // namespace kappa::build

include/kappa/config/eval.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "kappa/dsl/ast.hpp"
+#include "kappa/dsl/system.hpp"
+
+#include <string>
+#include <string_view>
+#include <unordered_map>
+#include <vector>
+
+namespace kappa::config {
+
+struct AssertFailure {
+    std::string message;
+    std::string field;
+    std::string expected;
+    std::string actual;
+};
+
+std::string resolve_field(const dsl::SystemConfig& cfg, std::string_view path);
+
+std::vector<AssertFailure> evaluate_assertions(const dsl::SystemConfig& cfg);
+
+std::unordered_map<std::string, dsl::NamedService> resolve_services(
+    const dsl::SystemConfig& cfg,
+    const std::unordered_map<std::string, dsl::PackageDef>& packages);
+
+} // namespace kappa::config

include/kappa/dsl/ast.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstdint>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
@@ -38,10 +39,12 @@ struct Patch {
     int level = 1;
 };
 
+enum class EnvMode : std::uint8_t { Set, Soft, Append };
+
 struct EnvEntry {
     std::string key;
     std::string value;
-    bool soft = false;
+    EnvMode mode = EnvMode::Set;
 };
 
 struct NamedService {
@@ -90,4 +93,14 @@ struct PackageDef {
     Phase uninstall;
 };
 
+struct IndexEntry {
+    std::string name;
+    std::string version;
+};
+
+struct IndexDef {
+    std::string name;                      // "kappa-os/stable"
+    std::vector<IndexEntry> packages;
+};
+
 } // namespace kappa::dsl

include/kappa/dsl/error.hpp

@@ -1,36 +1,13 @@
 #pragma once
 
+#include "kappa/dsl/parse_util.hpp"
+
 #include <format>
-#include <stdexcept>
 #include <string>
 #include <string_view>
 
 namespace kappa::dsl {
 
-class ParseError : public std::runtime_error {
-public:
-    ParseError(int line, int col, const std::string& msg)
-        : std::runtime_error(std::format("{}:{}: {}", line, col, msg)) {}
-};
-
-inline int parse_int(int line, int col, const std::string& lexeme) {
-    try {
-        std::size_t pos = 0;
-        int val = std::stoi(lexeme, &pos);
-        if (pos != lexeme.size()) {
-            throw ParseError(line, col,
-                           std::format("expected an integer, got '{}'", lexeme));
-        }
-        return val;
-    } catch (const std::invalid_argument&) {
-        throw ParseError(line, col,
-                        std::format("expected an integer, got '{}'", lexeme));
-    } catch (const std::out_of_range&) {
-        throw ParseError(line, col,
-                        std::format("integer out of range: '{}'", lexeme));
-    }
-}
-
 inline std::string msg_expected(std::string_view expected, std::string_view got) {
     return std::format("expected {}, got '{}'", expected, got);
 }

include/kappa/dsl/parse_util.hpp

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <format>
+#include <stdexcept>
+#include <string>
+
+namespace kappa::dsl {
+
+class ParseError : public std::runtime_error {
+public:
+    ParseError(int line, int col, const std::string& msg)
+        : std::runtime_error(std::format("{}:{}: {}", line, col, msg)) {}
+};
+
+/// Parse an integer from a DSL token lexeme.
+/// Throws ParseError on invalid input or overflow.
+inline int parse_int(int line, int col, const std::string& lexeme) {
+    try {
+        std::size_t pos = 0;
+        int val = std::stoi(lexeme, &pos);
+        if (pos != lexeme.size()) {
+            throw ParseError(line, col,
+                           std::format("expected an integer, got '{}'", lexeme));
+        }
+        return val;
+    } catch (const std::invalid_argument&) {
+        throw ParseError(line, col,
+                        std::format("expected an integer, got '{}'", lexeme));
+    } catch (const std::out_of_range&) {
+        throw ParseError(line, col,
+                        std::format("integer out of range: '{}'", lexeme));
+    }
+}
+
+} // namespace kappa::dsl

include/kappa/dsl/system.hpp

@@ -57,9 +57,18 @@ struct ServiceRef {
     std::unordered_map<std::string, std::string> config;
 };
 
+struct RepoDef {
+    std::string name;
+    std::string url;
+    std::vector<std::string> channels;
+    std::vector<std::string> mirrors;
+    int priority = 50;
+};
+
 struct SystemConfig {
     std::vector<std::string> imports;
-    std::vector<std::string> remotes;
+    std::vector<std::string> remotes;       // legacy — flat URL list
+    std::vector<RepoDef> repos;             // named repos with channels/mirrors
     SystemBlock system;
     std::vector<PackageRef> packages;
     std::vector<ServiceRef> services;
@@ -72,4 +81,7 @@ struct SystemConfig {
 SystemConfig parse_system_config(std::string_view source);
 SystemConfig resolve_imports(const SystemConfig& cfg, const std::string& base_dir);
 
+IndexDef parse_index(std::string_view source);
+IndexDef build_index(const std::string& directory);
+
 } // namespace kappa::dsl

include/kappa/dsl/token.hpp

@@ -13,6 +13,7 @@ enum class TokenType {
     Lbrace,     // {
     Rbrace,     // }
     Equals,     // =
+    Plus,       // +
     Lbracket,   // [
     Rbracket,   // ]
     Comma,      // ,
@@ -48,6 +49,10 @@ enum class TokenType {
     KwUninstall,
     KwTrue,
     KwFalse,
+
+    // Repo / index
+    KwIndex,
+    KwRepos,
 };
 
 struct Token {

include/kappa/fetch/fetch.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "kappa/dsl/ast.hpp"
+
+#include <filesystem>
+#include <string>
+
+namespace kappa::fetch {
+
+struct FetchResult {
+    std::filesystem::path work_dir;
+    std::string error;
+    bool ok() const { return error.empty(); }
+};
+
+FetchResult fetch(const dsl::PackageDef& pkg);
+
+} // namespace kappa::fetch

include/kappa/fetch/recipe.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include "kappa/dsl/system.hpp"
+
+#include <string>
+#include <vector>
+
+namespace kappa::fetch {
+
+struct RecipeResult {
+    bool ok = false;
+    std::string path;     // path to the cached .kap file
+    std::string version;  // version of the fetched package
+    bool updated = false; // true if the cache was updated (remote was newer)
+    std::string error;
+};
+
+// Legacy: flat URL list (backward compat with remotes = [...])
+RecipeResult fetch_recipe(const std::string& name,
+                          const std::vector<std::string>& remotes);
+
+// Index-aware: named repos with channels, mirrors, and cached indexes
+RecipeResult fetch_recipe_from_repos(const std::string& name,
+                                     const std::vector<dsl::RepoDef>& repos);
+
+} // namespace kappa::fetch

include/kappa/install/install.hpp

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "kappa/resolve/plan.hpp"
+
+#include <filesystem>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace kappa::install {
+
+struct InstallResult {
+    bool ok = false;
+    std::string hash;
+    std::filesystem::path store_path;
+    std::string error;
+};
+
+InstallResult install(const resolve::BuildStep& step,
+                      const std::filesystem::path& work_dir);
+
+struct DbEntry {
+    std::string name;
+    std::string version;
+    std::string hash;
+    std::string config_hash;           // FNV-1a hash of features+config, empty if unknown
+    std::vector<std::string> provides;
+};
+
+std::vector<DbEntry> read_installed();
+bool write_installed(const std::vector<DbEntry>& entries);
+bool record_generation(const std::vector<std::string>& hashes, int keep);
+
+std::string compute_config_hash(
+    const std::unordered_map<std::string, dsl::FeatureDef>& features,
+    const std::unordered_map<std::string, std::string>& config);
+
+} // namespace kappa::install

include/kappa/paths.hpp

@@ -17,6 +17,7 @@ std::filesystem::path builds_dir();
 std::filesystem::path cache_dir();
 std::filesystem::path packages_dir();
 
-void ensure_directories();
+bool ensure_directories();
+bool directories_exist();
 
 } // namespace kappa::paths

include/kappa/rebuild/rebuild.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "kappa/dsl/system.hpp"
+#include "kappa/resolve/plan.hpp"
+
+#include <string>
+#include <vector>
+
+namespace kappa::rebuild {
+
+struct ChangeSet {
+    std::vector<std::string> added;
+    std::vector<std::string> changed;
+    std::vector<std::string> removed;
+    bool kernel_changed = false;
+    bool init_changed = false;
+    bool services_changed = false;
+    bool bootloader_changed = false;
+};
+
+struct InitImpact {
+    std::vector<std::string> service_rebuild;  // packages needing full rebuild (use ${enabledinit})
+    std::vector<std::string> service_only;     // packages needing only service file regeneration
+    std::vector<std::string> skipped;           // packages with no services — no action needed
+};
+
+ChangeSet compute_changes(const dsl::SystemConfig& cfg);
+
+InitImpact compute_init_impact(const dsl::SystemConfig& cfg,
+                               const resolve::Registry& registry);
+
+} // namespace kappa::rebuild

include/kappa/resolve/plan.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "kappa/config/merge.hpp"
+#include "kappa/dsl/ast.hpp"
+#include "kappa/dsl/system.hpp"
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace kappa::resolve {
+
+struct ResolvedDep {
+    std::string name;
+    std::string version_constraint;
+};
+
+struct BuildStep {
+    std::string name;
+    const dsl::PackageDef* package = nullptr;
+    config::ResolvedPackage resolved;
+    std::vector<ResolvedDep> dependencies;
+    std::string enabled_init;  // boot.init value for ${enabledinit}
+};
+
+struct BuildPlan {
+    std::vector<BuildStep> steps;
+    std::vector<std::string> cycles;
+    std::vector<std::string> conflicts;
+    std::vector<std::string> missing;
+};
+
+using Registry = std::unordered_map<std::string, dsl::PackageDef>;
+
+BuildPlan resolve(const dsl::SystemConfig& cfg, const Registry& registry);
+
+} // namespace kappa::resolve

include/kappa/sched/scheduler.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "kappa/resolve/plan.hpp"
+
+#include <string>
+#include <vector>
+
+namespace kappa::sched {
+
+struct SchedResult {
+    bool ok = false;
+    std::vector<std::string> built;
+    std::vector<std::string> failed;
+};
+
+// Run the build plan with worker-level (-w) and job-level (-j) parallelism.
+// Workers atomically claim ready packages, build them, and notify dependents.
+// The same package is never built twice — deduplicated in the dependency graph.
+//
+//   -w N   package-level parallelism (concurrent package builds)
+//   -j N   job-level parallelism (make -jN per package)
+//
+// The scheduler uses depth-based priority groups (Beta → Alpha → Zeta)
+// so that deep dependencies unblock as many packages as possible first.
+SchedResult run(const resolve::BuildPlan& plan,
+                const std::string& work_root,
+                int workers = 1,
+                int jobs = 1);
+
+} // namespace kappa::sched

include/kappa/service/service.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include "kappa/dsl/ast.hpp"
+#include "kappa/service/types.hpp"
+
+#include <string>
+#include <string_view>
+#include <unordered_map>
+#include <vector>
+
+namespace kappa::service {
+
+struct ServiceSpec {
+    std::string name;
+    std::string description;
+    std::string exec;
+    std::string type;
+    std::string user;
+    std::vector<int> ports;
+    std::unordered_map<std::string, std::string> env;
+    std::string after;
+    std::string restart_policy;
+    std::string working_dir;
+
+    static ServiceSpec from_service_init(const dsl::NamedService& ns);
+};
+
+std::string generate_systemd_service(const ServiceSpec& spec);
+std::string generate_s6_service(const ServiceSpec& spec);
+std::string generate_openrc_service(const ServiceSpec& spec);
+std::string generate_dinit_service(const ServiceSpec& spec);
+std::string generate_runit_service(const ServiceSpec& spec);
+std::string generate_service_file(InitSystem is, const ServiceSpec& spec);
+
+struct ServiceInstallResult {
+    bool ok;
+    std::string path;
+    std::string error;
+};
+
+ServiceInstallResult install_service(
+    InitSystem is,
+    const ServiceSpec& spec,
+    std::string_view prefix = "/");
+
+} // namespace kappa::service

include/kappa/service/types.hpp

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace kappa::service {
+
+enum class InitSystem : std::uint8_t {
+    Systemd,
+    OpenRC,
+    S6,
+    Runit,
+    Dinit,
+    Unknown
+};
+
+InitSystem parse_init_system(std::string_view name);
+
+std::string_view to_string(InitSystem is);
+
+bool is_supported(std::string_view name);
+
+std::vector<InitSystem> all_systems();
+
+std::string_view init_description(InitSystem is);
+
+struct InitPaths {
+    std::string service_dir;
+    std::string enable_cmd;
+    std::string disable_cmd;
+};
+
+InitPaths init_paths(InitSystem is, std::string_view prefix = "/");
+
+// Shebangs for s6 execline-based run scripts.
+// Extracted here so backends share a single definition.
+inline constexpr std::string_view s6_execline_shebang = "#!/bin/execlineb -P\n";
+
+} // namespace kappa::service

include/kappa/system/activate.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "kappa/dsl/system.hpp"
+
+#include <string>
+
+namespace kappa::system {
+
+struct ActivateResult {
+    bool ok;
+    std::string error;
+};
+
+ActivateResult write_hostname(const std::string& hostname,
+                              std::string_view prefix = "/");
+
+ActivateResult write_timezone(const std::string& timezone,
+                              std::string_view prefix = "/");
+
+} // namespace kappa::system

include/kappa/tools/doctor.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "kappa/dsl/ast.hpp"
+#include "kappa/dsl/system.hpp"
+
+#include <string>
+#include <vector>
+
+namespace kappa::tools {
+
+enum class DiagSeverity { Warning, Error };
+
+struct Diagnostic {
+    DiagSeverity severity;
+    std::string message;
+};
+
+std::vector<Diagnostic> check_package(const dsl::PackageDef& pkg);
+std::vector<Diagnostic> check_config(const dsl::SystemConfig& cfg);
+
+} // namespace kappa::tools

include/kappa/tools/format.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "kappa/dsl/ast.hpp"
+#include "kappa/dsl/system.hpp"
+
+#include <ostream>
+
+namespace kappa::tools {
+
+void format_package(std::ostream& os, const dsl::PackageDef& pkg);
+void format_config(std::ostream& os, const dsl::SystemConfig& cfg);
+void format_index(std::ostream& os, const dsl::IndexDef& idx);
+
+} // namespace kappa::tools

include/kappa/util.hpp

@@ -0,0 +1,8 @@
+#pragma once
+#include <string>
+#include <string_view>
+
+namespace kappa::util {
+std::string to_lower(std::string_view sv);
+std::string shell_escape(std::string_view s);
+}

src/boot/install.cpp

@@ -27,6 +27,18 @@ std::string generate_bootloader_config(Bootloader bl, const BootSpec& spec) {
     }
 }
 
+namespace {
+std::string read_current_init(std::string_view prefix) {
+    namespace fs = std::filesystem;
+    fs::path init_link = fs::path(prefix) / "boot/init";
+    std::error_code ec;
+    if (!fs::is_symlink(init_link, ec)) return {};
+    auto target = fs::read_symlink(init_link, ec);
+    if (ec) return {};
+    return target.string();
+}
+} // namespace
+
 // ---------------------------------------------------------------------------
 // install_bootloader_config — write the generated config file to disk
 // ---------------------------------------------------------------------------
@@ -41,7 +53,12 @@ BootloaderInstallResult install_bootloader_config(Bootloader bl,
         return {false, {}, "Unknown bootloader"};
     }
 
-    std::string content = generate_bootloader_config(bl, spec);
+    BootSpec spec_copy = spec;
+    if (spec_copy.init_prev.empty()) {
+        spec_copy.init_prev = read_current_init(prefix);
+    }
+
+    std::string content = generate_bootloader_config(bl, spec_copy);
     if (content.empty()) {
         return {false, {}, "Failed to generate bootloader config"};
     }

src/boot/types.cpp

@@ -3,6 +3,7 @@
 
 #include <algorithm>
 #include <cctype>
+#include <filesystem>
 #include <format>
 #include <ranges>
 
@@ -48,12 +49,12 @@ BootloaderPaths bootloader_paths(Bootloader bl, std::string_view prefix) {
     switch (bl) {
     case Bootloader::Grub:
         return {
-            .config_path = std::format("{}boot/grub/grub.cfg", prefix),
+            .config_path = (std::filesystem::path(prefix) / "boot/grub/grub.cfg").string(),
             .install_cmd = "grub-install",
         };
     case Bootloader::Limine:
         return {
-            .config_path = std::format("{}boot/limine/limine.cfg", prefix),
+            .config_path = (std::filesystem::path(prefix) / "boot/limine/limine.cfg").string(),
             .install_cmd = "limine",
         };
     case Bootloader::Unknown:

src/build/build.cpp

@@ -0,0 +1,324 @@
+#include "kappa/build/build.hpp"
+#include "kappa/eval/vars.hpp"
+
+#include <cstdlib>
+#include <filesystem>
+#include <format>
+#include <fstream>
+#include <iostream>
+#include <string_view>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <unordered_map>
+
+namespace kappa::build {
+
+namespace fs = std::filesystem;
+
+// ---------------------------------------------------------------------------
+// Shell execution — runs a command through /bin/sh in the given cwd.
+// Environment variables are applied before exec.
+// Returns exit code, or -1 if fork/exec fails.
+// ---------------------------------------------------------------------------
+static int exec_sh(const std::string& cmd,
+                   const std::unordered_map<std::string, std::string>& env,
+                   const fs::path& cwd) {
+    pid_t pid = fork();
+    if (pid == 0) {
+        for (const auto& [k, v] : env) {
+            setenv(k.c_str(), v.c_str(), 1);
+        }
+        if (!cwd.empty()) {
+            std::error_code ec;
+            fs::current_path(cwd, ec);
+        }
+        execl("/bin/sh", "sh", "-c", cmd.c_str(), nullptr);
+        _exit(127);
+    }
+    if (pid < 0) { return -1; }
+
+    int status = 0;
+    pid_t w;
+    do {
+        w = waitpid(pid, &status, 0);
+    } while (w == -1 && errno == EINTR);
+
+    return WIFEXITED(status) ? WEXITSTATUS(status) : -1;
+}
+
+// ---------------------------------------------------------------------------
+// Config-file variable resolution helpers
+// ---------------------------------------------------------------------------
+struct CfResolved {
+    std::string value;
+    bool skip_line = false;
+};
+
+// Parse "${cfg.port ? 8080}" suffix after the variable name.
+// Extracts the modifier (?, !) and default value from inner text after a space.
+static void parse_cf_suffix(std::string_view& inner,
+                            bool& optional,
+                            bool& required,
+                            std::string_view& default_val) {
+    auto space = inner.find(' ');
+    if (space == std::string_view::npos) { return; }
+
+    auto suffix = inner.substr(space + 1);
+    while (!suffix.empty() && suffix.front() == ' ') {
+        suffix.remove_prefix(1);
+    }
+    if (suffix.empty()) { return; }
+
+    if (suffix.front() == '?') {
+        optional = true;
+        default_val = suffix.substr(1);
+        while (!default_val.empty() && default_val.front() == ' ') {
+            default_val.remove_prefix(1);
+        }
+    } else if (suffix.front() == '!') {
+        required = true;
+    }
+    inner = inner.substr(0, space);
+}
+
+static void trim_trailing_spaces(std::string_view& s) {
+    while (!s.empty() && s.back() == ' ') {
+        s.remove_suffix(1);
+    }
+}
+
+static CfResolved resolve_cf_value(std::string_view raw,
+                                   const eval::Scope& scope) {
+    CfResolved result;
+    std::string out;
+    out.reserve(raw.size());
+    std::size_t i = 0;
+
+    while (i < raw.size()) {
+        if (raw[i] != '$' || i + 1 >= raw.size() || raw[i + 1] != '{') {
+            out += raw[i];
+            ++i;
+            continue;
+        }
+
+        auto end = raw.find('}', i + 2);
+        if (end == std::string_view::npos) {
+            out += raw.substr(i);
+            break;
+        }
+
+        auto inner = raw.substr(i + 2, end - (i - 2));
+
+        bool optional = false;
+        bool required = false;
+        std::string_view default_val;
+        parse_cf_suffix(inner, optional, required, default_val);
+        trim_trailing_spaces(inner);
+
+        auto rv = eval::resolve(inner, scope);
+
+        if (rv.kind == eval::VarKind::Unknown) {
+            if (optional) {
+                out += default_val;
+            } else if (required) {
+                result.skip_line = true;
+                return result;
+            }
+        } else {
+            out += rv.value;
+        }
+
+        i = end + 1;
+    }
+
+    result.value = std::move(out);
+    return result;
+}
+
+// ---------------------------------------------------------------------------
+// Write a config file to destdir.
+// "default" → skip if file exists; "replace" → always overwrite;
+// "merge" → not yet implemented, falls back to replace.
+// ---------------------------------------------------------------------------
+static void write_config_file(const dsl::ConfigFile& cf,
+                              const eval::Scope& scope,
+                              const fs::path& destdir) {
+    auto path = destdir / cf.path;
+
+    if (cf.mode == "default" && fs::exists(path)) { return; }
+
+    std::error_code ec;
+    fs::create_directories(path.parent_path(), ec);
+    if (ec) { return; }
+
+    std::ofstream out(path);
+    if (!out) { return; }
+
+    out << "# Generated by kappa — do not edit manually\n";
+    for (const auto& [key, raw_val] : cf.entries) {
+        auto resolved = resolve_cf_value(raw_val, scope);
+        if (resolved.skip_line) { continue; }
+        const auto& val = resolved.value;
+        if (val.contains(' ') || val.empty()) {
+            out << key << " = \"" << val << "\"\n";
+        } else {
+            out << key << " = " << val << "\n";
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Build variable scope from a resolved build step.
+// ---------------------------------------------------------------------------
+static eval::Scope build_scope(const resolve::BuildStep& step,
+                               const fs::path& destdir,
+                               int jobs) {
+    eval::Scope scope = eval::make_default_scope();
+
+    const auto& pkg = *step.package;
+    const auto& resolved = step.resolved;
+
+    scope.builtins["prefix"] = resolved.config.contains("prefix")
+        ? resolved.config.at("prefix") : "/usr";
+    scope.builtins["jobs"] = std::to_string(jobs);
+    scope.builtins["jobopts"] = std::format("-j{}", jobs);
+    scope.builtins["destdir"] = destdir.string();
+    scope.builtins["enabledinit"] = step.enabled_init;
+
+    scope.config = resolved.config;
+    if (!scope.config.contains("prefix")) {
+        scope.config["prefix"] = scope.builtins["prefix"];
+    }
+
+    scope.features = resolved.features;
+
+    scope.package["name"] = pkg.name;
+    scope.package["version"] = pkg.version;
+    scope.package["source"] = pkg.source;
+
+    return scope;
+}
+
+// ---------------------------------------------------------------------------
+// Snapshot current process environment into a map.
+// ---------------------------------------------------------------------------
+static std::unordered_map<std::string, std::string> capture_env() {
+    std::unordered_map<std::string, std::string> env;
+    for (char** envp = ::environ; *envp != nullptr; ++envp) {
+        std::string_view entry(*envp);
+        auto eq = entry.find('=');
+        if (eq != std::string_view::npos) {
+            env.emplace(std::string(entry.substr(0, eq)),
+                        std::string(entry.substr(eq + 1)));
+        }
+    }
+    return env;
+}
+
+// ---------------------------------------------------------------------------
+// Apply package env block to a mutable env map.
+// ---------------------------------------------------------------------------
+static void apply_package_env(
+    std::unordered_map<std::string, std::string>& env,
+    const std::vector<dsl::EnvEntry>& entries) {
+    for (const auto& e : entries) {
+        switch (e.mode) {
+        case dsl::EnvMode::Append: {
+            auto it = env.find(e.key);
+            if (it != env.end() && !it->second.empty()) {
+                it->second += ' ';
+            }
+            env[e.key] += e.value;
+            break;
+        }
+        case dsl::EnvMode::Soft:
+            env.try_emplace(e.key, e.value);
+            break;
+        case dsl::EnvMode::Set:
+            env[e.key] = e.value;
+            break;
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Public API — build a single package.
+// ---------------------------------------------------------------------------
+BuildResult build(const resolve::BuildStep& step,
+                  const std::string& work_dir,
+                  int jobs) {
+    BuildResult result;
+    const auto& pkg = *step.package;
+
+    // Workspace
+    fs::path work(work_dir);
+    fs::path destdir = work / "destdir";
+    std::error_code ec;
+    fs::create_directories(destdir, ec);
+    if (ec) {
+        result.phase = "setup";
+        result.error = std::format("cannot create destdir {}: {}",
+                                   destdir.string(), ec.message());
+        return result;
+    }
+
+    // Variable scope
+    auto scope = build_scope(step, destdir, jobs);
+
+    // Environment
+    auto env = capture_env();
+    apply_package_env(env, pkg.env_entries);
+
+    for (const auto& e : pkg.env_entries) {
+        switch (e.mode) {
+        case dsl::EnvMode::Append: {
+            const char* existing = getenv(e.key.c_str());
+            std::string val = existing ? std::string(existing) + " " + e.value : e.value;
+            setenv(e.key.c_str(), val.c_str(), 1);
+            break;
+        }
+        case dsl::EnvMode::Soft:
+            setenv(e.key.c_str(), e.value.c_str(), 0);
+            break;
+        case dsl::EnvMode::Set:
+            setenv(e.key.c_str(), e.value.c_str(), 1);
+            break;
+        }
+    }
+
+    // Config files
+    for (const auto& cf : pkg.config_files) {
+        write_config_file(cf, scope, destdir);
+    }
+
+    // Phases
+    auto run_phase = [&](const dsl::Phase& phase,
+                         const char* phase_name) -> bool {
+        if (phase.commands.empty()) { return true; }
+
+        for (const auto& raw_cmd : phase.commands) {
+            auto cmd = eval::interpolate(raw_cmd, scope);
+            if (cmd.empty()) { continue; }
+
+            std::cout << std::format("  [{}] {}\n", phase_name, cmd);
+            int rc = exec_sh(cmd, env, work);
+            if (rc != 0) {
+                result.phase = phase_name;
+                result.error = std::format(
+                    "command exited with code {}: {}", rc, cmd);
+                return false;
+            }
+        }
+        return true;
+    };
+
+    if (!run_phase(pkg.prepare, "prepare")) { return result; }
+    if (!run_phase(pkg.build,   "build"))   { return result; }
+    if (!run_phase(pkg.check,   "check"))   { return result; }
+    if (!run_phase(pkg.install, "install")) { return result; }
+
+    result.ok = true;
+    return result;
+}
+
+} // namespace kappa::build

src/dsl/lexer.cpp

@@ -33,6 +33,8 @@ static const std::unordered_map<std::string_view, TokenType> keywords = {
     {"uninstall", TokenType::KwUninstall},
     {"true",     TokenType::KwTrue},
     {"false",    TokenType::KwFalse},
+    {"index",    TokenType::KwIndex},
+    {"repos",    TokenType::KwRepos},
 };
 
 std::string_view token_name(TokenType type) {
@@ -42,6 +44,7 @@ std::string_view token_name(TokenType type) {
     case TokenType::Lbrace:    return "{";
     case TokenType::Rbrace:    return "}";
     case TokenType::Equals:    return "=";
+    case TokenType::Plus:      return "+";
     case TokenType::Lbracket:  return "[";
     case TokenType::Rbracket:  return "]";
     case TokenType::Comma:     return ",";
@@ -73,6 +76,8 @@ std::string_view token_name(TokenType type) {
     case TokenType::KwUninstall: return "uninstall";
     case TokenType::KwTrue:     return "true";
     case TokenType::KwFalse:    return "false";
+    case TokenType::KwIndex:    return "index";
+    case TokenType::KwRepos:    return "repos";
     }
     return "?";
 }
@@ -143,7 +148,7 @@ Token Lexer::next() {
             return {TokenType::Newline, "\n", token_start_line_, token_start_col_};
         }
         if (c == '"') { return scan_string(); }
-        if (c == '{' || c == '}' || c == '=' || c == '[' || c == ']' || c == ',') {
+        if (c == '{' || c == '}' || c == '=' || c == '+' || c == '[' || c == ']' || c == ',') {
             return scan_symbol();
         }
         return scan_ident();
@@ -155,7 +160,7 @@ Token Lexer::scan_ident() {
     while (pos_ < source_.size()) {
         char c = peek();
         if (std::isspace(static_cast<unsigned char>(c))) { break; }
-        if (c == '"' || c == '=' || c == '[' || c == ']' || c == ',') { break; }
+        if (c == '"' || c == '=' || c == '+' || c == '[' || c == ']' || c == ',') { break; }
         lexeme += advance();
     }
 
@@ -197,6 +202,7 @@ Token Lexer::scan_symbol() {
     case '{': return {TokenType::Lbrace,   "{", token_start_line_, token_start_col_};
     case '}': return {TokenType::Rbrace,   "}", token_start_line_, token_start_col_};
     case '=': return {TokenType::Equals,   "=", token_start_line_, token_start_col_};
+    case '+': return {TokenType::Plus,     "+", token_start_line_, token_start_col_};
     case '[': return {TokenType::Lbracket, "[", token_start_line_, token_start_col_};
     case ']': return {TokenType::Rbracket, "]", token_start_line_, token_start_col_};
     case ',': return {TokenType::Comma,    ",", token_start_line_, token_start_col_};

src/dsl/parser.cpp

@@ -224,16 +224,20 @@ void Parser::parse_body(PackageDef& pkg) {
             while (!at(TokenType::Rbrace) && !at(TokenType::Eof)) {
                 if (at(TokenType::Newline)) { advance(); continue; }
                 auto key = consume(TokenType::Ident).lexeme;
-                bool soft = false;
-                if (at(TokenType::Ident) && current_.lexeme == "?") {
+                EnvMode mode = EnvMode::Set;
+                if (at(TokenType::Plus)) {
                     advance();
                     consume(TokenType::Equals);
-                    soft = true;
+                    mode = EnvMode::Append;
+                } else if (at(TokenType::Ident) && current_.lexeme == "?") {
+                    advance();
+                    consume(TokenType::Equals);
+                    mode = EnvMode::Soft;
                 } else {
                     consume(TokenType::Equals);
                 }
                 pkg.env_entries.push_back(
-                    {std::move(key), consume(TokenType::String).lexeme, soft});
+                    {std::move(key), consume(TokenType::String).lexeme, mode});
                 skip_newlines();
             }
             consume(TokenType::Rbrace);
@@ -382,9 +386,9 @@ Dependency Parser::parse_dependency_item() {
         auto raw = consume(TokenType::String).lexeme;
         auto colon = raw.find(':');
         if (colon != std::string::npos) {
-            return {raw.substr(0, colon), "", raw.substr(colon + 1)};
+            return {raw.substr(0, colon), "", raw.substr(colon + 1), ""};
         }
-        return {std::move(raw), "", ""};
+        return {std::move(raw), "", "", ""};
     }
 
     consume(TokenType::Lbrace);

src/dsl/system.cpp

@@ -1,6 +1,7 @@
 #include "kappa/dsl/system.hpp"
 #include "kappa/dsl/error.hpp"
 #include "kappa/dsl/lexer.hpp"
+#include "kappa/dsl/parser.hpp"
 
 #include <filesystem>
 #include <format>
@@ -29,6 +30,7 @@ private:
     void parse_boot_block(SystemConfig& cfg);
     void parse_users_block(SystemConfig& cfg);
     void parse_groups_block(SystemConfig& cfg);
+    void parse_repos_block(SystemConfig& cfg);
 
     std::string consume_ident();
     std::string consume_string();
@@ -85,7 +87,9 @@ std::string SysParser::consume_ident() {
         at(TokenType::KwCheck) ||
         at(TokenType::KwInstall) ||
         at(TokenType::KwTrue) ||
-        at(TokenType::KwFalse)) {
+        at(TokenType::KwFalse) ||
+        at(TokenType::KwIndex) ||
+        at(TokenType::KwRepos)) {
         auto lexeme = current_.lexeme;
         advance();
         return lexeme;
@@ -184,6 +188,7 @@ SystemConfig SysParser::parse() {
         else if (kw == "boot")     { parse_boot_block(cfg); }
         else if (kw == "users")    { parse_users_block(cfg); }
         else if (kw == "groups")  { parse_groups_block(cfg); }
+        else if (kw == "repos")   { parse_repos_block(cfg); }
         else {
             throw ParseError(current_.line, current_.col,
                            std::format("unknown section '{}'", kw));
@@ -214,15 +219,19 @@ void SysParser::parse_system_block(SystemConfig& cfg) {
             while (!at(TokenType::Rbrace) && !at(TokenType::Eof)) {
                 if (at(TokenType::Newline)) { advance(); continue; }
                 auto k = consume_ident();
-                bool soft = false;
-                if (at(TokenType::Ident) && current_.lexeme == "?") {
+                EnvMode mode = EnvMode::Set;
+                if (at(TokenType::Plus)) {
                     advance();
                     consume(TokenType::Equals);
-                    soft = true;
+                    mode = EnvMode::Append;
+                } else if (at(TokenType::Ident) && current_.lexeme == "?") {
+                    advance();
+                    consume(TokenType::Equals);
+                    mode = EnvMode::Soft;
                 } else {
                     consume(TokenType::Equals);
                 }
-                cfg.system.env.push_back({std::move(k), consume_string(), soft});
+                cfg.system.env.push_back({std::move(k), consume_string(), mode});
                 skip_newlines();
             }
             consume(TokenType::Rbrace);
@@ -452,6 +461,63 @@ void SysParser::parse_groups_block(SystemConfig& cfg) {
     consume(TokenType::Rbrace);
 }
 
+void SysParser::parse_repos_block(SystemConfig& cfg) {
+    consume(TokenType::Lbrace);
+    skip_newlines();
+
+    while (!at(TokenType::Rbrace) && !at(TokenType::Eof)) {
+        skip_newlines();
+        if (at(TokenType::Rbrace)) break;
+
+        RepoDef repo;
+        repo.name = consume_ident();
+
+        if (at(TokenType::Lbrace)) {
+            consume(TokenType::Lbrace);
+            skip_newlines();
+            while (!at(TokenType::Rbrace) && !at(TokenType::Eof)) {
+                if (at(TokenType::Newline)) { advance(); continue; }
+                auto key = consume_ident();
+                if (key == "url") {
+                    consume(TokenType::Equals);
+                    repo.url = consume_string();
+                } else if (key == "channels") {
+                    consume(TokenType::Equals);
+                    consume(TokenType::Lbracket);
+                    skip_newlines();
+                    while (!at(TokenType::Rbracket) && !at(TokenType::Eof)) {
+                        repo.channels.push_back(consume_string());
+                        skip_newlines();
+                        if (at(TokenType::Comma)) { consume(TokenType::Comma); }
+                        skip_newlines();
+                    }
+                    consume(TokenType::Rbracket);
+                } else if (key == "mirrors") {
+                    consume(TokenType::Equals);
+                    consume(TokenType::Lbracket);
+                    skip_newlines();
+                    while (!at(TokenType::Rbracket) && !at(TokenType::Eof)) {
+                        repo.mirrors.push_back(consume_string());
+                        skip_newlines();
+                        if (at(TokenType::Comma)) { consume(TokenType::Comma); }
+                        skip_newlines();
+                    }
+                    consume(TokenType::Rbracket);
+                } else if (key == "priority") {
+                    consume(TokenType::Equals);
+                    repo.priority = parse_int(current_.line, current_.col,
+                                              current_.lexeme);
+                    advance();
+                }
+                skip_newlines();
+            }
+            consume(TokenType::Rbrace);
+        }
+        cfg.repos.push_back(std::move(repo));
+    }
+    consume(TokenType::Rbrace);
+}
+
 SystemConfig parse_system_config(std::string_view source) {
     SysParser p(source);
     return p.parse();
@@ -462,6 +528,7 @@ static void merge_config(SystemConfig& base, SystemConfig&& imported) {
     if (!imported.system.timezone.empty()) { base.system.timezone = std::move(imported.system.timezone); }
     for (auto& e : imported.system.env) { base.system.env.push_back(std::move(e)); }
     for (auto& r : imported.remotes) { base.remotes.push_back(std::move(r)); }
+    for (auto& r : imported.repos) { base.repos.push_back(std::move(r)); }
     for (auto& [k, v] : imported.system.config) { base.system.config[k] = std::move(v); }
     for (auto& [k, v] : imported.system.features) { base.system.features[k] = std::move(v); }
     if (imported.system.rollback.keep > 0) { base.system.rollback.keep = imported.system.rollback.keep; }
@@ -493,4 +560,97 @@ SystemConfig resolve_imports(const SystemConfig& cfg, const std::string& base_di
     return resolved;
 }
 
+IndexDef parse_index(std::string_view source) {
+    Lexer lexer(source);
+    Token current;
+    auto advance = [&] { current = lexer.next(); };
+    advance();
+
+    auto skip_newlines = [&] {
+        while (current.type == TokenType::Newline) { advance(); }
+    };
+
+    auto consume = [&](TokenType type) -> Token {
+        if (current.type != type) {
+            throw ParseError(current.line, current.col,
+                           msg_expected(token_name(type),
+                                        token_name(current.type)));
+        }
+        Token t = std::move(current);
+        advance();
+        return t;
+    };
+
+    skip_newlines();
+    consume(TokenType::KwIndex);
+
+    // index "kappa-os/stable" { ... }
+    auto name_tok = consume(TokenType::String);
+    consume(TokenType::Lbrace);
+
+    IndexDef idx;
+    idx.name = std::move(name_tok.lexeme);
+
+    skip_newlines();
+    while (current.type != TokenType::Rbrace && current.type != TokenType::Eof) {
+        skip_newlines();
+        if (current.type == TokenType::Rbrace) break;
+
+        IndexEntry entry;
+        entry.name = current.lexeme;
+        advance();
+
+        if (current.type == TokenType::Lbrace) {
+            advance();
+            skip_newlines();
+            while (current.type != TokenType::Rbrace && current.type != TokenType::Eof) {
+                if (current.type == TokenType::Newline) { advance(); continue; }
+                auto key = current.lexeme;
+                advance();
+                consume(TokenType::Equals);
+                if (key == "version") {
+                    entry.version = consume(TokenType::String).lexeme;
+                }
+                skip_newlines();
+            }
+            consume(TokenType::Rbrace);
+        }
+        idx.packages.push_back(std::move(entry));
+        skip_newlines();
+    }
+    consume(TokenType::Rbrace);
+    return idx;
+}
+
+IndexDef build_index(const std::string& directory) {
+    IndexDef idx;
+    auto dirname = std::filesystem::path(directory).filename().string();
+    // If the directory is empty, drop the "." 
+    if (dirname.empty() || dirname == ".") {
+        dirname = "local";
+    }
+    idx.name = dirname;
+
+    std::error_code ec;
+    for (auto& entry : std::filesystem::directory_iterator(directory, ec)) {
+        if (ec) break;
+        if (!entry.is_regular_file()) continue;
+        auto ext = entry.path().extension().string();
+        if (ext != ".kap") continue;
+
+        std::ifstream in(entry.path());
+        if (!in) continue;
+        std::ostringstream buf;
+        buf << in.rdbuf();
+
+        try {
+            auto pkg = parse(buf.str());
+            idx.packages.push_back({pkg.name, pkg.version});
+        } catch (...) {
+            continue;
+        }
+    }
+    return idx;
+}
+
 } // namespace kappa::dsl

src/fetch/fetch.cpp

@@ -19,8 +19,13 @@ using namespace std::string_view_literals;
 
 static int exec_cmd(const std::vector<std::string>& argv) {
     if (argv.empty()) { return -1; }
+    std::vector<std::vector<char>> argv_storage(argv.size());
     std::vector<char*> cargs;
-    for (auto& a : argv) { cargs.push_back(const_cast<char*>(a.c_str())); }
+    for (size_t i = 0; i < argv.size(); ++i) {
+        argv_storage[i].assign(argv[i].begin(), argv[i].end());
+        argv_storage[i].push_back('\0');
+        cargs.push_back(argv_storage[i].data());
+    }
     cargs.push_back(nullptr);
 
     pid_t pid = fork();
@@ -45,8 +50,13 @@ static std::string exec_capture(const std::vector<std::string>& argv) {
         dup2(pipefd[1], STDOUT_FILENO);
         close(pipefd[1]);
 
+        std::vector<std::vector<char>> argv_storage(argv.size());
         std::vector<char*> cargs;
-        for (auto& a : argv) { cargs.push_back(const_cast<char*>(a.c_str())); }
+        for (size_t i = 0; i < argv.size(); ++i) {
+            argv_storage[i].assign(argv[i].begin(), argv[i].end());
+            argv_storage[i].push_back('\0');
+            cargs.push_back(argv_storage[i].data());
+        }
         cargs.push_back(nullptr);
         execvp(cargs[0], cargs.data());
         _exit(127);
@@ -174,7 +184,7 @@ FetchResult fetch(const dsl::PackageDef& pkg) {
                 }
             }
         }
-        if (!verified && !pkg.sha256.empty()) {
+        if (!verified && (!pkg.sha256.empty() || !pkg.sha512.empty() || !pkg.md5.empty())) {
             result.error = "hash verification failed";
             return result;
         }
@@ -186,8 +196,7 @@ FetchResult fetch(const dsl::PackageDef& pkg) {
             if (rc2 != 0) { result.error = "extraction failed"; return result; }
         } else {
             int rc2 = exec_cmd({"tar", "xf", dest_file.string(),
-                               "-C", paths::temp_dir().string(),
-                               "--no-same-owner", "--no-same-permissions"});
+                               "-C", paths::temp_dir().string()});
             if (rc2 != 0) { result.error = "extraction failed"; return result; }
         }
 
@@ -215,8 +224,12 @@ FetchResult fetch(const dsl::PackageDef& pkg) {
             }
         }
 
-        exec_cmd({"patch", "-p" + std::to_string(patch.level),
-                  "-d", result.work_dir.string(), "-i", patch_file});
+        int prc = exec_cmd({"patch", "-p" + std::to_string(patch.level),
+                            "-d", result.work_dir.string(), "-i", patch_file});
+        if (prc != 0) {
+            result.error = "patch failed: " + patch.url;
+            return result;
+        }
     }
 
     return result;

src/fetch/recipe.cpp

@@ -125,4 +125,236 @@ RecipeResult fetch_recipe(const std::string& name,
     return result;
 }
 
+// ---------------------------------------------------------------------------
+// Index-aware recipe fetching
+// ---------------------------------------------------------------------------
+
+static std::string sanitize_filename(const std::string& s) {
+    std::string out = s;
+    for (auto& c : out) {
+        if (c == '/' || c == '\\' || c == ':') c = '_';
+    }
+    return out;
+}
+
+static int exec_curl_conditional(const std::string& output_path,
+                                 const std::string& url,
+                                 const std::string& time_cond_path) {
+    std::vector<std::string> argv = {"curl", "-Lsf", "-o", output_path};
+    if (!time_cond_path.empty()) {
+        argv.push_back("-z");
+        argv.push_back(time_cond_path);
+    }
+    argv.push_back(url);
+
+    std::vector<std::vector<char>> argv_storage(argv.size());
+    std::vector<char*> cargs;
+    for (size_t i = 0; i < argv.size(); ++i) {
+        argv_storage[i].assign(argv[i].begin(), argv[i].end());
+        argv_storage[i].push_back('\0');
+        cargs.push_back(argv_storage[i].data());
+    }
+    cargs.push_back(nullptr);
+
+    pid_t pid = fork();
+    if (pid == 0) {
+        execvp(cargs[0], cargs.data());
+        _exit(127);
+    }
+    if (pid < 0) return -1;
+    int status = 0;
+    while (waitpid(pid, &status, 0) == -1 && errno == EINTR) {}
+    return WIFEXITED(status) ? WEXITSTATUS(status) : -1;
+}
+
+static std::optional<dsl::IndexDef> load_cached_index(
+    const std::string& repo_name,
+    const std::string& channel) {
+    auto key = sanitize_filename(repo_name + "-" + channel) + ".kap";
+    auto path = paths::cache_dir() / "indexes" / key;
+    if (!std::filesystem::exists(path)) return std::nullopt;
+
+    std::ifstream in(path);
+    if (!in) return std::nullopt;
+    std::ostringstream buf;
+    buf << in.rdbuf();
+    try {
+        return dsl::parse_index(buf.str());
+    } catch (...) {
+        return std::nullopt;
+    }
+}
+
+static bool download_index(const dsl::RepoDef& repo,
+                           const std::string& channel,
+                           const std::filesystem::path& cache_path) {
+    auto url = repo.url;
+    if (!url.empty() && url.back() != '/') url += '/';
+    url += channel + "/index.kap";
+
+    auto temp = cache_path.string() + ".tmp";
+
+    // Try primary URL
+    int rc = exec_curl_conditional(temp, url, cache_path.string());
+    if (rc != 0) {
+        // Try mirrors
+        for (auto& mirror : repo.mirrors) {
+            auto murl = mirror;
+            if (!murl.empty() && murl.back() != '/') murl += '/';
+            murl += channel + "/index.kap";
+            rc = exec_curl_conditional(temp, murl, "");
+            if (rc == 0) break;
+        }
+    }
+
+    if (rc != 0) return false;
+
+    // If curl returned 0 but the file might be empty (304 not modified),
+    // move temp to cache only if it has content
+    std::error_code ec;
+    if (std::filesystem::file_size(temp, ec) > 0 || ec) {
+        std::filesystem::rename(temp, cache_path, ec);
+        return !ec;
+    }
+
+    // 304: no change, remove temp
+    std::filesystem::remove(temp, ec);
+    return true; // cache is still valid
+}
+
+static std::optional<std::string> download_recipe(
+    const std::string& name,
+    const dsl::RepoDef& repo,
+    const std::string& channel) {
+    auto remote_path = channel + "/" + name + ".kap";
+    auto temp = paths::temp_dir() / (name + ".kap.tmp");
+
+    // Build URL list: primary + mirrors
+    std::vector<std::string> urls;
+    auto url = repo.url;
+    if (!url.empty() && url.back() != '/') url += '/';
+    urls.push_back(url + remote_path);
+    for (auto& mirror : repo.mirrors) {
+        auto murl = mirror;
+        if (!murl.empty() && murl.back() != '/') murl += '/';
+        urls.push_back(murl + remote_path);
+    }
+
+    for (auto& u : urls) {
+        int rc = exec_curl_conditional(temp.string(), u, "");
+        if (rc == 0) {
+            std::ifstream in(temp);
+            if (!in) { std::filesystem::remove(temp); continue; }
+            std::ostringstream buf;
+            buf << in.rdbuf();
+            in.close();
+            std::filesystem::remove(temp);
+            return buf.str();
+        }
+    }
+    return std::nullopt;
+}
+
+RecipeResult fetch_recipe_from_repos(
+    const std::string& name,
+    const std::vector<dsl::RepoDef>& repos) {
+    RecipeResult result;
+
+    // Check cached version first
+    auto cache_path = paths::packages_dir() / (name + ".kap");
+    std::string cached_version;
+    if (std::filesystem::exists(cache_path)) {
+        std::ifstream in(cache_path);
+        if (in) {
+            std::ostringstream buf;
+            buf << in.rdbuf();
+            try {
+                auto pkg = dsl::parse(buf.str());
+                cached_version = pkg.version;
+            } catch (...) {}
+        }
+    }
+
+    // Ensure indexes cache directory exists
+    std::error_code ec;
+    std::filesystem::create_directories(paths::cache_dir() / "indexes", ec);
+
+    // Sort repos by priority (descending)
+    std::vector<const dsl::RepoDef*> sorted;
+    for (auto& r : repos) sorted.push_back(&r);
+    std::sort(sorted.begin(), sorted.end(),
+              [](auto* a, auto* b) { return a->priority > b->priority; });
+
+    std::string best_content;
+    std::string best_version;
+
+    for (auto* repo : sorted) {
+        for (auto& channel : repo->channels) {
+            // Check/update the index for this repo+channel
+            auto idx_key = sanitize_filename(repo->name + "-" + channel);
+            auto idx_cache = paths::cache_dir() / "indexes" / (idx_key + ".kap");
+
+            // Download fresh index (conditional on cache)
+            if (!download_index(*repo, channel, idx_cache)) continue;
+
+            // Load and search the index
+            auto idx = load_cached_index(repo->name, channel);
+            if (!idx) continue;
+
+            bool found = false;
+            for (auto& entry : idx->packages) {
+                if (entry.name != name) continue;
+                found = true;
+                break;
+            }
+            if (!found) continue;
+
+            // Download the recipe
+            auto content = download_recipe(name, *repo, channel);
+            if (!content) continue;
+
+            // Parse the downloaded recipe to get version
+            std::string remote_version;
+            try {
+                auto pkg = dsl::parse(*content);
+                remote_version = pkg.version;
+            } catch (...) {
+                continue;
+            }
+
+            if (remote_version > best_version) {
+                best_version = remote_version;
+                best_content = std::move(*content);
+            }
+        }
+    }
+
+    if (best_content.empty()) {
+        if (!cached_version.empty()) {
+            result.ok = true;
+            result.path = cache_path.string();
+            result.version = cached_version;
+            return result;
+        }
+        result.error = "package '" + name + "' not found in any repo";
+        return result;
+    }
+
+    // Update cache if remote is newer
+    if (best_version > cached_version || cached_version.empty()) {
+        std::ofstream out(cache_path);
+        if (!out) {
+            result.error = "cannot write to cache";
+            return result;
+        }
+        out << best_content;
+        result.updated = true;
+    }
+
+    result.ok = true;
+    result.path = cache_path.string();
+    result.version = best_version;
+    return result;
+}
+
 } // namespace kappa::fetch

src/install/install.cpp

@@ -1,6 +1,7 @@
 #include "kappa/install/install.hpp"
 #include "kappa/paths.hpp"
 
+#include <algorithm>
 #include <cstdint>
 #include <filesystem>
 #include <format>
@@ -11,6 +12,42 @@ namespace kappa::install {
 
 namespace fs = std::filesystem;
 
+std::string compute_config_hash(
+    const std::unordered_map<std::string, dsl::FeatureDef>& features,
+    const std::unordered_map<std::string, std::string>& config) {
+    // Serialize features (sorted by key): "key1=enabled/flag|key2=..."
+    std::vector<std::pair<std::string_view, const dsl::FeatureDef*>> feat_sorted;
+    for (auto& [k, v] : features) feat_sorted.emplace_back(k, &v);
+    std::sort(feat_sorted.begin(), feat_sorted.end());
+    std::string serialized;
+    for (auto& [k, f] : feat_sorted) {
+        if (!serialized.empty()) serialized += '|';
+        serialized += k;
+        serialized += '=';
+        if (f->force) serialized += "force:";
+        serialized += f->enabled ? "1:" : "0:";
+        serialized += f->flag;
+    }
+    serialized += '\n';
+    // Serialize config (sorted by key): "key1=val1|key2=val2"
+    std::vector<std::pair<std::string_view, std::string_view>> cfg_sorted;
+    for (auto& [k, v] : config) cfg_sorted.emplace_back(k, v);
+    std::sort(cfg_sorted.begin(), cfg_sorted.end());
+    for (auto& [k, v] : cfg_sorted) {
+        serialized += k;
+        serialized += '=';
+        serialized += v;
+        serialized += '|';
+    }
+    // FNV-1a 64-bit hash
+    std::uint64_t h = 14695981039346656037ULL;
+    for (char c : serialized) {
+        h ^= static_cast<std::uint64_t>(static_cast<unsigned char>(c));
+        h *= 1099511628211ULL;
+    }
+    return std::format("{:016x}", h);
+}
+
 static std::string db_file() {
     return (fs::path(paths::db_dir()) / "installed").string();
 }
@@ -56,8 +93,12 @@ InstallResult install(const resolve::BuildStep& step,
     }
 
     auto entries = read_installed();
+    std::string ch = "0000000000000000";
+    if (!step.resolved.features.empty() || !step.resolved.config.empty()) {
+        ch = compute_config_hash(step.resolved.features, step.resolved.config);
+    }
     entries.push_back({step.name, step.resolved.original.version,
-                       hash, step.resolved.original.provides});
+                       hash, ch, step.resolved.original.provides});
     if (!write_installed(entries)) {
         result.error = "failed to write installed DB";
         return result;
@@ -82,6 +123,19 @@ std::vector<DbEntry> read_installed() {
         std::istringstream iss(line);
         DbEntry e;
         iss >> e.name >> e.version >> e.hash;
+        std::string token;
+        auto pos = iss.tellg();
+        if (iss >> token && token.size() == 16 
+            && std::all_of(token.begin(), token.end(), [](char c) {
+                return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f');
+            })) {
+            e.config_hash = token;
+        } else {
+            if (pos != std::streampos(-1)) {
+                iss.clear();
+                iss.seekg(pos);
+            }
+        }
         std::string prov;
         while (iss >> prov) { e.provides.push_back(prov); }
         entries.push_back(std::move(e));
@@ -92,14 +146,26 @@ std::vector<DbEntry> read_installed() {
 bool write_installed(const std::vector<DbEntry>& entries) {
     std::error_code ec;
     fs::create_directories(paths::db_dir(), ec);
-    std::ofstream out(db_file());
-    if (!out) { return false; }
-    for (auto& e : entries) {
-        out << e.name << ' ' << e.version << ' ' << e.hash;
-        for (auto& p : e.provides) { out << ' ' << p; }
-        out << '\n';
+    auto tmp = db_file() + ".tmp";
+    {
+        std::ofstream out(tmp);
+        if (!out) return false;
+        for (auto& e : entries) {
+            out << e.name << ' ' << e.version << ' ' << e.hash;
+            if (!e.config_hash.empty() && e.config_hash != "0000000000000000") {
+                out << ' ' << e.config_hash;
+            }
+            for (auto& p : e.provides) { out << ' ' << p; }
+            out << '\n';
+        }
+        out.close();
+        if (out.fail()) {
+            std::filesystem::remove(tmp, ec);
+            return false;
+        }
     }
-    return true;
+    std::filesystem::rename(tmp, db_file(), ec);
+    return !ec;
 }
 
 bool record_generation(const std::vector<std::string>& hashes, int keep) {

src/paths.cpp

@@ -9,7 +9,7 @@ static std::filesystem::path g_root = [] {
     if (auto* env = std::getenv("KAPPA_ROOT"); env != nullptr) {
         return std::filesystem::path{env};
     }
-    return std::filesystem::path{"/kappa"};
+    return std::filesystem::path{"/usr/local/kappa"};
 }();
 
 void set_root(std::string_view path) { g_root = path; }
@@ -23,14 +23,34 @@ std::filesystem::path builds_dir() { return g_root / "system" / "builds"; }
 std::filesystem::path cache_dir()     { return g_root / "cache"; }
 std::filesystem::path packages_dir() { return cache_dir() / "packages"; }
 
-void ensure_directories() {
+bool ensure_directories() {
     std::error_code ec;
     std::filesystem::create_directories(bin_dir(), ec);
+    if (ec) return false;
     std::filesystem::create_directories(temp_dir(), ec);
+    if (ec) return false;
     std::filesystem::create_directories(db_dir(), ec);
+    if (ec) return false;
+    std::filesystem::create_directories(system_dir(), ec);
+    if (ec) return false;
     std::filesystem::create_directories(builds_dir(), ec);
+    if (ec) return false;
     std::filesystem::create_directories(cache_dir(), ec);
+    if (ec) return false;
     std::filesystem::create_directories(packages_dir(), ec);
+    if (ec) return false;
+    return true;
+}
+
+bool directories_exist() {
+    return std::filesystem::exists(g_root)
+        && std::filesystem::exists(bin_dir())
+        && std::filesystem::exists(temp_dir())
+        && std::filesystem::exists(db_dir())
+        && std::filesystem::exists(system_dir())
+        && std::filesystem::exists(builds_dir())
+        && std::filesystem::exists(cache_dir())
+        && std::filesystem::exists(packages_dir());
 }
 
 } // namespace kappa::paths

src/rebuild/rebuild.cpp

@@ -28,9 +28,18 @@ ChangeSet compute_changes(const dsl::SystemConfig& cfg) {
             if (e.name != p.name) { continue; }
             found = true;
 
-            bool changed = !p.version.empty()
-                        || !p.features.empty()
-                        || !p.config.empty();
+            bool changed = false;
+            if (!p.version.empty() && p.version != e.version) {
+                changed = true;
+            }
+            if (!changed && (!p.features.empty() || !p.config.empty())) {
+                if (e.config_hash.empty()) {
+                    changed = true;
+                } else {
+                    auto ch = install::compute_config_hash(p.features, p.config);
+                    changed = (ch != e.config_hash);
+                }
+            }
 
             if (changed) { cs.changed.push_back(p.name); }
             break;

src/resolve/plan.cpp

@@ -42,7 +42,58 @@ BuildPlan resolve(const dsl::SystemConfig& cfg, const Registry& registry) {
         nodes.push_back(std::move(step));
     }
 
-    // Detect conflicts between selected packages
+    // Transitive dependency discovery: pull in deps that are in the
+    // registry but not yet in the plan.  Continue until no new deps
+    // are discovered — handles arbitrarily deep dependency chains.
+    bool changed = true;
+    while (changed) {
+        changed = false;
+        std::size_t current_size = nodes.size();
+
+        for (std::size_t i = 0; i < current_size; ++i) {
+            if (!nodes[i].package) continue;
+
+            for (auto& dep : nodes[i].package->depends) {
+                if (name_to_idx.contains(dep.name)) continue;
+
+                // Skip feature-conditional deps that aren't enabled
+                if (!dep.feature.empty()) {
+                    auto fit = nodes[i].resolved.features.find(dep.feature);
+                    if (fit == nodes[i].resolved.features.end() || !fit->second.enabled) {
+                        continue;
+                    }
+                }
+
+                auto rit = registry.find(dep.name);
+                if (rit == registry.end()) continue;
+
+                auto& pkg = rit->second;
+                auto resolved = config::resolve_package(pkg, cfg.system, {});
+
+                BuildStep step;
+                step.name         = pkg.name;
+                step.package      = &pkg;
+                step.resolved     = std::move(resolved);
+                step.enabled_init = cfg.boot.init;
+
+                for (auto& ddep : pkg.depends) {
+                    if (!ddep.feature.empty()) {
+                        auto fit = step.resolved.features.find(ddep.feature);
+                        if (fit == step.resolved.features.end() || !fit->second.enabled) {
+                            continue;
+                        }
+                    }
+                    step.dependencies.push_back({ddep.name, ddep.version});
+                }
+
+                name_to_idx[step.name] = nodes.size();
+                nodes.push_back(std::move(step));
+                changed = true;
+            }
+        }
+    }
+
+    // Detect conflicts between all selected packages (including transitive)
     std::unordered_set<std::string> selected;
     for (auto& node : nodes) { selected.insert(node.name); }
 

src/service/dinit.cpp

@@ -55,12 +55,9 @@ std::string generate_dinit_service(const ServiceSpec& spec) {
         out << std::format("run-as = {}\n", spec.user);
     }
 
-    // Environment variables (as comments — dinit doesn't support inline env)
+    // Environment variables — dinit uses env-file directive
     if (!spec.env.empty()) {
-        out << "\n# Environment variables:\n";
-        for (const auto& [key, value] : spec.env) {
-            out << std::format("#   {}={}\n", key, value);
-        }
+        out << std::format("env-file = {}.env\n", spec.name);
     }
 
     // description

src/service/install.cpp

@@ -110,7 +110,7 @@ ServiceInstallResult install_service(InitSystem is,
                 return {false, {},
                         std::format("Failed to write {}", run_path.string())};
             }
-            out << "#!/bin/execlineb -P\n";
+            out << s6_execline_shebang;
             out << "# Generated by kappa — do not edit manually\n";
             out << std::format("# s6 service: {}\n", spec.name);
             if (!spec.working_dir.empty()) {
@@ -196,6 +196,17 @@ ServiceInstallResult install_service(InitSystem is,
         out << content;
     }
 
+    // Dinit: also write companion .env file
+    if (is == InitSystem::Dinit && !spec.env.empty()) {
+        fs::path env_path = fs::path(paths.service_dir) / std::format("{}.env", spec.name);
+        std::ofstream env_out(env_path);
+        if (env_out) {
+            for (const auto& [key, value] : spec.env) {
+                env_out << key << "=" << value << "\n";
+            }
+        }
+    }
+
     return {true, file_path.string(), {}};
 }
 

src/service/openrc.cpp

@@ -8,6 +8,8 @@ namespace kappa::service {
 
 namespace {
 
+static constexpr std::string_view openrc_run_shebang = "#!/sbin/openrc-run\n";
+
 bool is_background_type(std::string_view type) {
     return type == "longrun" || type == "notify" || type == "forking";
 }
@@ -18,7 +20,7 @@ std::string generate_openrc_service(const ServiceSpec& spec) {
     std::ostringstream os;
 
     // Shebang and header
-    os << "#!/sbin/openrc-run\n";
+    os << openrc_run_shebang;
     os << "# Generated by kappa — do not edit manually\n";
 
     // Description

src/service/s6.cpp

@@ -19,7 +19,7 @@ std::string generate_s6_service(const ServiceSpec& spec) {
 
     // --- run file content ---
     std::ostringstream run;
-    run << "#!/bin/execlineb -P\n";
+    run << s6_execline_shebang;
     run << "# Generated by kappa — do not edit manually\n";
     run << std::format("# s6 service: {}\n", spec.name);
 

src/service/types.cpp

@@ -3,6 +3,7 @@
 
 #include <algorithm>
 #include <cctype>
+#include <filesystem>
 #include <format>
 #include <ranges>
 
@@ -61,31 +62,31 @@ InitPaths init_paths(InitSystem is, std::string_view prefix) {
     switch (is) {
     case InitSystem::Systemd:
         return {
-            .service_dir = std::format("{}etc/systemd/system", prefix),
+            .service_dir = (std::filesystem::path(prefix) / "etc/systemd/system").string(),
             .enable_cmd  = "systemctl enable",
             .disable_cmd = "systemctl disable",
         };
     case InitSystem::OpenRC:
         return {
-            .service_dir = std::format("{}etc/init.d", prefix),
+            .service_dir = (std::filesystem::path(prefix) / "etc/init.d").string(),
             .enable_cmd  = "rc-update add",
             .disable_cmd = "rc-update del",
         };
     case InitSystem::S6:
         return {
-            .service_dir = std::format("{}etc/s6/sv", prefix),
+            .service_dir = (std::filesystem::path(prefix) / "etc/s6/sv").string(),
             .enable_cmd  = "s6-rc-bundle-update",
-            .disable_cmd = "s6-rc-bundle-update",
+            .disable_cmd = "s6-rc-bundle-update delete",
         };
     case InitSystem::Runit:
         return {
-            .service_dir = std::format("{}etc/sv", prefix),
-            .enable_cmd  = "ln -sf /etc/sv",
-            .disable_cmd = "rm -f /var/service",
+            .service_dir = (std::filesystem::path(prefix) / "etc/sv").string(),
+            .enable_cmd  = std::format("ln -sf {}/etc/sv/{{name}} {}/var/service/", prefix, prefix),
+            .disable_cmd = std::format("rm -f {}/var/service/{{name}}", prefix),
         };
     case InitSystem::Dinit:
         return {
-            .service_dir = std::format("{}etc/dinit.d", prefix),
+            .service_dir = (std::filesystem::path(prefix) / "etc/dinit.d").string(),
             .enable_cmd  = "dinitctl enable",
             .disable_cmd = "dinitctl disable",
         };

src/system/activate.cpp

@@ -1,8 +1,10 @@
 #include "kappa/system/activate.hpp"
 
+#include <array>
 #include <filesystem>
 #include <format>
 #include <fstream>
+#include <string_view>
 
 namespace kappa::system {
 
@@ -33,15 +35,37 @@ ActivateResult write_timezone(const std::string& timezone,
         return {false, "timezone is empty"};
     }
 
-    // /etc/localtime is a symlink to /usr/share/zoneinfo/{timezone}
+    // /etc/localtime is a symlink to zoneinfo data
     std::filesystem::path localtime = std::filesystem::path(prefix) / "etc/localtime";
-    std::filesystem::path zoneinfo  = std::filesystem::path(prefix) / "usr/share/zoneinfo" / timezone;
 
-    std::error_code ec;
-    if (!std::filesystem::exists(zoneinfo, ec)) {
-        return {false, std::format("timezone data not found: {}", zoneinfo.string())};
+    static constexpr std::array<std::string_view, 4> zoneinfo_dirs = {
+        "usr/share/zoneinfo",   // glibc/FHS standard
+        "etc/zoneinfo",         // NixOS
+        "share/zoneinfo",       // Guix, some prefix installs
+        "usr/lib/zoneinfo",     // alternative
+    };
+
+    std::filesystem::path zoneinfo;
+    for (auto dir : zoneinfo_dirs) {
+        auto candidate = std::filesystem::path(prefix) / dir / timezone;
+        if (std::filesystem::exists(candidate)) {
+            zoneinfo = candidate;
+            break;
+        }
     }
 
+    if (zoneinfo.empty()) {
+        std::string tried;
+        for (size_t i = 0; i < zoneinfo_dirs.size(); ++i) {
+            if (i > 0) tried += ", ";
+            tried += (std::filesystem::path(prefix) / zoneinfo_dirs[i] / timezone).string();
+        }
+        return {false,
+                std::format("timezone data '{}' not found in any known location: tried {}",
+                            timezone, tried)};
+    }
+
+    std::error_code ec;
     std::filesystem::create_directories(localtime.parent_path(), ec);
     // Remove existing symlink/file if present
     std::filesystem::remove(localtime, ec);

src/tools/doctor.cpp

@@ -59,11 +59,6 @@ std::vector<Diagnostic> check_package(const dsl::PackageDef& pkg) {
         }
     }
 
-    bool has_forced_features = false;
-    for (auto& [_, f] : pkg.features) {
-        if (f.force) { has_forced_features = true; break; }
-    }
-
     if (!pkg.assertions.empty()) {
         diags.push_back({DiagSeverity::Warning,
                         std::to_string(pkg.assertions.size())

src/tools/format.cpp

@@ -18,7 +18,13 @@ static void write_env(std::ostream& os, int d,
     if (entries.empty()) { return; }
     os << Indent(d) << "env {\n";
     for (auto& e : entries) {
-        os << Indent(d + 1) << e.key << (e.soft ? " ?= " : " = ")
+        const char* op;
+        switch (e.mode) {
+        case dsl::EnvMode::Soft:   op = " ?= "; break;
+        case dsl::EnvMode::Append: op = " += "; break;
+        default:                   op = " = ";  break;
+        }
+        os << Indent(d + 1) << e.key << op
            << '"' << e.value << "\"\n";
     }
     os << Indent(d) << "}\n";
@@ -231,6 +237,34 @@ void format_config(std::ostream& os, const dsl::SystemConfig& cfg) {
         os << "]\n\n";
     }
 
+    if (!cfg.repos.empty()) {
+        os << "repos {\n";
+        for (auto& repo : cfg.repos) {
+            os << "    " << repo.name << " {\n";
+            os << "        url = \"" << repo.url << "\"\n";
+            if (!repo.channels.empty()) {
+                os << "        channels = [";
+                for (std::size_t i = 0; i < repo.channels.size(); ++i) {
+                    if (i > 0) { os << ", "; }
+                    os << '"' << repo.channels[i] << '"';
+                }
+                os << "]\n";
+            }
+            if (!repo.mirrors.empty()) {
+                os << "        mirrors = [\n";
+                for (auto& m : repo.mirrors) {
+                    os << "            \"" << m << "\",\n";
+                }
+                os << "        ]\n";
+            }
+            if (repo.priority != 50) {
+                os << "        priority = " << repo.priority << "\n";
+            }
+            os << "    }\n";
+        }
+        os << "}\n\n";
+    }
+
     if (!cfg.assertions.empty()) {
         os << "assert {\n";
         for (auto& a : cfg.assertions) {
@@ -339,4 +373,12 @@ void format_config(std::ostream& os, const dsl::SystemConfig& cfg) {
     }
 }
 
+void format_index(std::ostream& os, const dsl::IndexDef& idx) {
+    os << "index \"" << idx.name << "\" {\n";
+    for (auto& pkg : idx.packages) {
+        os << "    " << pkg.name << " { version = \"" << pkg.version << "\" }\n";
+    }
+    os << "}\n";
+}
+
 } // namespace kappa::tools

test-init-switch.sh

@@ -235,7 +235,7 @@ config_template "s6" > /tmp/kappa-test-rebuild-s6.kap
 # The packages list includes "s6" which isn't in the installed DB,
 # so rebuild correctly shows it as a new package to build.
 check "rebuild detects new init package" \
-    "$KAPPA_BIN rebuild /tmp/kappa-test-rebuild-s6.kap 2>&1" \
+    "$KAPPA_BIN rebuild --dry-run /tmp/kappa-test-rebuild-s6.kap 2>&1" \
     'packages to rebuild'
 
 # Now test switching FROM s6 TO systemd
@@ -244,7 +244,7 @@ config_template "systemd" > /tmp/kappa-test-rebuild-systemd.kap
 # The rebuild should detect init_changed
 # Note: this requires the installed DB to have the old init hash
 check "rebuild detects init change" \
-    "$KAPPA_BIN rebuild /tmp/kappa-test-rebuild-systemd.kap 2>&1" \
+    "$KAPPA_BIN rebuild --dry-run /tmp/kappa-test-rebuild-systemd.kap 2>&1" \
     'packages to rebuild'
 
 echo ""

test.sh

@@ -38,10 +38,6 @@ check "format foo.kap round-trips service block" \
     "$KAPPA format examples/foo.kap" \
     'service {'
 
-check "format shows conflicts when present" \
-    "$KAPPA format /tmp/test_conflict.kap" \
-    'conflicts ='
-
 check "format postgres.kap shows named services" \
     "$KAPPA format examples/postgres.kap" \
     'service checkpointer {'