This guide describes how to build and package the bitcoin-qt GUI for Android on Linux and macOS.
Before proceeding with an Android build one needs to get the Android SDK and use the "SDK Manager" tool to download the NDK and one or more "Platform packages" (these are Android versions and have a corresponding API level).
The minimum supported Android NDK version is r21.
In order to build ANDROID_API_LEVEL (API level corresponding to the Android version targeted, e.g. Android 9.0 Pie is 28 and its "Platform package" needs to be available) and ANDROID_TOOLCHAIN_BIN (path to toolchain binaries depending on the platform the build is being performed on) need to be set.
API levels from 24 to 29 have been tested to work.
If the build includes Qt, environment variables ANDROID_SDK and ANDROID_NDK need to be set as well but can otherwise be omitted.
This is an example command for a default build with no disabled dependencies:
ANDROID_SDK=/home/user/Android/Sdk ANDROID_NDK=/home/user/Android/Sdk/ndk-bundle make HOST=aarch64-linux-android ANDROID_API_LEVEL=28 ANDROID_TOOLCHAIN_BIN=/home/user/Android/Sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin
After the depends are built configure with one of the resulting prefixes and run make && make apk in src/qt.