minetest/doc/developing/android.md

Android tips & tricks

Sign the Android APK from CI

The Github Actions Workflow automatically produces an APK for each architecture. Before installing them onto a device they however need to be signed.

This requires an installation of the Android SDK and adb.

.../android-sdk/build-tools/30.0.3/apksigner sign --ks ~/.android/debug.keystore \
	app-arm64-v8a-release-unsigned.apk
# Enter 'android' (without quotes) when asked for a password

Note that the debug.keystore will not exist if you have never compiled an Android app on your system (probably).

After that installing it will work:

adb install -r -d ./app-arm64-v8a-release-unsigned.apk

How to get debug output from Luanti on Android

In case debug.txt isn't enough (e.g. when debugging a crash), you can get debug output using logcat:

adb logcat -s 'Minetest:*' '*:F'

Note that you can do this even after the app has crashed, since Android keeps an internal buffer.

A segmentation fault for example looks like this:

01-10 17:20:22.215 19308 20560 F libc    : Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 20560 (MinetestNativeT), pid 19308 (netest.minetest)
01-10 17:20:22.287 20576 20576 F DEBUG   : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
01-10 17:20:22.287 20576 20576 F DEBUG   : Build fingerprint: '...'
01-10 17:20:22.287 20576 20576 F DEBUG   : Revision: '4'
01-10 17:20:22.287 20576 20576 F DEBUG   : ABI: 'arm64'
01-10 17:20:22.288 20576 20576 F DEBUG   : Timestamp: 2024-01-10 17:20:22+0100
01-10 17:20:22.288 20576 20576 F DEBUG   : pid: 19308, tid: 20560, name: MinetestNativeT  >>> net.minetest.minetest <<<
01-10 17:20:22.288 20576 20576 F DEBUG   : uid: 10385
01-10 17:20:22.288 20576 20576 F DEBUG   : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault addr --------
[ ... more information follows ... ]

If you want get rid of previous output you can do that with adb logcat -c.

I edited builtin, shaders, ... but nothing changed. Help!

You're probably hitting two problems:

• the build system only generates assets once
• the app only re-extracts assets when the version changes

Force regenerating the assets: ./gradlew app:clean

Erase the app's memory of which version was installed: adb shell run-as net.minetest.minetest rm shared_prefs/MinetestSettings.xml

If this doesn't work you can also uninstall it using adb shell pm uninstall net.minetest.minetest. You will obviously lose your data.

Then build and install as normal and your changes should be applied.