Amend Android dev documentation

android/app/build.gradle

@@ -108,6 +108,10 @@ task prepareAssets() {
 preBuild.dependsOn zipAssets
 prepareAssets.dependsOn ':native:getDeps'
 
+clean {
+	delete new File("src/main/assets", "Minetest.zip")
+}
+
 // Map for the version code that gives each ABI a value.
 import com.android.build.OutputFile
 

doc/developing/README.md

@@ -15,6 +15,7 @@ Notable pages:
 ## In this folder
 
 - [Developing minetestserver with Docker](docker.md)
+- [Android tips & tricks](android.md)
 - [Miscellaneous](misc.md)
 
 ## IRC

doc/developing/android.md

@@ -0,0 +1,63 @@
+# Android tips & tricks
+
+## Sign the Android APK from CI
+
+The [Github Actions Workflow](https://github.com/minetest/minetest/actions?query=workflow%3Aandroid+event%3Apush)
+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`.
+```bash
+.../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:
+```bash
+adb install -r -d ./app-arm64-v8a-release-unsigned.apk
+```
+
+## How to get debug output from Minetest 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.

doc/developing/misc.md

@@ -1,51 +1,5 @@
 # Miscellaneous
 
-## Sign the Android APK from CI
-
-The [Github Actions Workflow](https://github.com/minetest/minetest/actions?query=workflow%3Aandroid+event%3Apush)
-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`.
-```bash
-.../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:
-```bash
-adb install -r -d ./app-arm64-v8a-release-unsigned.apk
-```
-
-## How to get debug output from Minetest 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 ... ]
-```
-
 ## Profiling Minetest on Linux
 
 We will be using a tool called "perf", which you can get by installing `perf` or `linux-perf` or `linux-tools-common`.