Android

Using the Android SDK

NixOS uses the androidenv package for building android SDKs and manually creating emulators without the use of Android Studio. Example android sdk is androidenv.androidPkgs_9_0.androidsdk. They also include all of the SDK tools such as sdkmanager and avdmanager needed to create emulators.

The first link provides a guide for creating a custom android SDK, using a predefined SDK, and how to nixify an emulator. The second link is an extra guide that might have some helpful tips for improving your workflow.

1. Official Android SDK guide from NixOS.org
2. Reproducing Android app deployments

When creating emulators with Nix's emulateApp function as mentioned in the first link, your IDE should now be able to recognize the emulator but you won't be able to run the code. To run it, view the first link on how to run the apk file in the emulator.

To run emulateApp, build it with nix-build fileName.nix. It'll build in the folder result. run it with ./result/bin/run-test-emulator

Creating emulators without Nix

If you don't want to nixify your emulators, you can use Android Studio and set up emulators there like a regular system.

Using sdkmanager and avdmanager from the Android SDK may not work given how Nix stores its files. You can use them from the Android Studio GUI.

When using machine images from the SDK, you will need to run them with steam-run, and possibly pass extra flags, e.g.:

steam-run ~/Android/Sdk/emulator/emulator -feature -Vulkan @Pixel_5_API_33

hardware acceleration

NOTE: Whether this here is effective needs more research and confirmation. My colleague and I have seen the emulator using around 800% CPU. So far, the following has improved that on my side.

See also the nixpkgs issue where people tried to trace issues.

Add your user to the kvm group:

{
  users.users.<your-user>.extraGroups = ["kvm"];
}

adb setup

To enable adb in NixOS for unprivileged users add these lines to your configuration.nix. This is mandatory for all further interactions with your android device.

{
  programs.adb.enable = true;
  users.users.<your-user>.extraGroups = ["adbusers"];
}

This will add additional udev rules for unprivileged access as well as add adb to your $PATH.

Alternatively, if you don't want to install adb globally but do want to configure the udev rules, you can:

{
  services.udev.packages = [
    pkgs.android-udev-rules
  ];
}

Use Older Platform Version

If you would like to get older platform version, you can write the following.

{ pkgs ? import <nixpkgs> { 
  config.android_sdk.accept_license = true;
  overlays = [
    (self: super: {
      androidPkgs_8_0 = super.androidenv.composeAndroidPackages {
        platformVersions = [ "26" ];
        abiVersions = [ "x86" "x86_64"];
      };
    })
  ];
} }:

(pkgs.buildFHSUserEnv {
  name = "android-sdk-env";
  targetPkgs = pkgs: (with pkgs;
    [
      androidPkgs_8_0.androidsdk
      glibc
    ]);
  runScript = "bash";
}).env

Interaction with your Android device

adb shell on device

First open a nix-shell with the platform tools and connect your device:

$ # For nixos < 19.03
$ # nix-shell -p androidenv.platformTools
$ nix-shell -p androidenv.androidPkgs_9_0.platform-tools
% adb devices
List of devices attached
* daemon not running; starting now at tcp:5037
* daemon started successfully
BH90272JCU	unauthorized

Troubleshooting: no device is listed

A popup appears on your phone to allow your computer access to it. After allowing, you can:

% adb devices
List of devices attached
BH90272JCU	device
% adb shell

You can also connect to an already-running adb server:

$ # For nixos < 19.03
$ # nix-shell -p androidenv.platformTools
$ nix-shell -p androidenv.androidPkgs_9_0.platform-tools
% adb connect 192.168.1.10
% adb shell

Transferring files from/to an Android device

There are two main methods for newer devices:

• adb push and adb pull: see above.
• via MTP, see the corresponding page

Android Development

Android Studio

To develop apps using Android Studio, install it to your system.

{
  pkgs.android-studio
}

gradlew

It's possible to create a build environment (shell.nix) to use with gradlew as a FHS environment:

{ pkgs ? import <nixpkgs> {config.android_sdk.accept_license = true;} }:

(pkgs.buildFHSUserEnv {
  name = "android-sdk-env";
  targetPkgs = pkgs: (with pkgs;
    [
      androidenv.androidPkgs_9_0.androidsdk
      glibc
    ]);
  runScript = "bash";
}).env

As an alternative, it's often enough to override just the aapt2 binary for the gradle build process:

{ pkgs ? import <nixpkgs> {config.android_sdk.accept_license = true;} }:

let
  androidSdk = pkgs.androidenv.androidPkgs_9_0.androidsdk;
in
pkgs.mkShell {
  buildInputs = with pkgs; [
    androidSdk
    glibc
  ];
  # override the aapt2 that gradle uses with the nix-shipped version
  GRADLE_OPTS = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${androidSdk}/libexec/android-sdk/build-tools/28.0.3/aapt2";
}

See the androidenv documentation for full examples.

Building Android on NixOS

It's possible to use nix-shell with buildFHSUserEnv to set up an environment in which it's viable to build Android without huge amounts of editing. This is an example shell.nix file.

{ pkgs ? import <nixpkgs> {} }:
 
let fhs = pkgs.buildFHSUserEnv {
  name = "android-env";
  targetPkgs = pkgs: with pkgs;
    [ git
      gitRepo
      gnupg
      python2
      curl
      procps
      openssl
      gnumake
      nettools
      # For nixos < 19.03, use `androidenv.platformTools`
      androidenv.androidPkgs_9_0.platform-tools
      jdk
      schedtool
      util-linux
      m4
      gperf
      perl
      libxml2
      zip
      unzip
      bison
      flex
      lzop
      python3
    ];
  multiPkgs = pkgs: with pkgs;
    [ zlib
      ncurses5
    ];
  runScript = "bash";
  profile = ''
    export ALLOW_NINJA_ENV=true
    export USE_CCACHE=1
    export ANDROID_JAVA_HOME=${pkgs.jdk.home}sdkmanager install avd
    export LD_LIBRARY_PATH=/usr/lib:/usr/lib32
  '';
};
in pkgs.stdenv.mkDerivation {
  name = "android-env-shell";
  nativeBuildInputs = [ fhs ];
  shellHook = "exec android-env";

}

1. more information on that snippet
2. A shell.nix to build LineageOS
3. robotnix, building aosp roms (e.g. LineageOS) with nix.
4. LineageOS build setup using terranix and hcloud, based on the shell.nix to build LineageOS. Useful if you are in a rush and don't have to much CPU power on your hand.