Mobile has been a target that has been mostly supported by the codebase for a long time, but I could never figure out how to build it in a coherent way - initial versions built the APK using Ant, a now-deprecated (and removed) build system, and newer things like Gradle and Maven have proved difficult to work with and require the full Android SDK which is now forcefully bundled with Android Studio. tldr Google are pretty messy :)
But here we are! Building with the Android CLI, replicating the build environment on Windows and Linux is exactly the same and just requires a handful of commands which only install CLI tools. Building and deploying to a wireless device connected to adb is
make target=android run. Rebuilding a couple of source files and sending to the device takes around 10 seconds. Probably as good as it's going to get!