nix

Reproducible Flutter builds on macOS, iOS, and Android using Nix.

Nix pins system dependencies (ruby, cocoapods, cmake, etc.) so every developer gets identical versions. Xcode and the Android NDK handle native compilation; Nix supplies the surrounding tooling.

Reproducibility

Builds from the same pinned configuration are deterministic on a given machine. macOS .app bundles are byte-identical across clean rebuilds. Android APK file contents are also byte-identical; the only variance is the APK Signature v2 block, which changes because cryptographic signing is inherently non-deterministic.

Pinning happens at three layers:

• Nix packages are locked in nix/flake.lock.
• Flutter SDK version is set in flutter_version.env.
• Android SDK component versions are set in android_sdk_version.env.
• Dart packages are locked in pubspec.lock.

Setup

1. Install Nix with flakes enabled:

   # ~/.config/nix/nix.conf
   experimental-features = nix-command flakes
   

2. macOS/iOS requires Xcode:

   sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
   sudo xcodebuild -runFirstLaunch

3. Android requires JDK 17+. Install Android Studio or point JAVA_HOME at any compatible JDK.

Quick start

# macOS/iOS
make setup            # pin flake + fetch Flutter SDK
make shell            # enter dev shell
flutter run -d macos

# Android
make setup-android    # fetch Flutter + Android SDK
make shell-android
flutter run -d emulator-5554

See the Makefile for all targets (build-macos, build-android, shell-pinned, etc.).

Nix and Xcode compatibility

Nix's mkShell injects compiler wrappers and environment variables that conflict with Xcode. The shellHook in flake.nix unsets these so that Nix provides tools while Xcode owns all C/C++/Swift compilation.

Updating

What	How
Nix packages	make pin
Flutter SDK	edit flutter_version.env, then make setup
Android SDK	edit android_sdk_version.env, then make setup-android
Dart packages	flutter pub upgrade

License

MIT. See LICENSE.