Android Development with 32bit Linux (Debian)

Google removed support for 32bit Linux for there build-tools for Android. Last officially supported version is 23.0.3. This version is too old for current development.

The main problem is that aapt2 is a 64bit executable and won't run on 32bit.

Lately I found a solution for this problem. You can emulate a 64bit system for exactly one executable with qemu.
But when just running it you will see the missing libraries.

Those are in /lib/x86_64-linux-gnu.

Setup

Obviously these libraries won't be found on a 32bit system because they are for 64bit. This means installing them with apt will be difficult (at least I don't know how).

• You will need libc6, libc6-dev, zlib1g and libgcc1. You should download the deb packages for your system (64bit instead of 32bit) into a new working folder.

• Create a folder fakeInstall in this folder.

• Now run:

  dpkg -x libc6_2.24-11+deb9u3_amd64.deb fakeInstall
  dpkg -x libc6-dev_2.24-11+deb9u3_amd64.deb fakeInstall
  dpkg -x zlib1g_1.2.8.dfsg-5_amd64.deb fakeInstall
  dpkg -x libgcc1_6.3.0-18+deb9u1_amd64.deb fakeInstall

  (update the versions to yours)

  This will install the packages into the fakeInstall folder.

• Now we need to put everything into the right place:
  (attention when working with sudo!)

  sudo mv fakeInstall/lib/x86_64-linux-gnu /lib/
  sudo mkdir -p /lib64
  sudo mv fakeInstall/lib64/ld-linux-x86-64.so.2 /lib64

• Basically the preparation is finished.
  So let's install qemu. Luckily it's in the default apt list
  (at least on debian stretch):

  sudo apt-get update
  sudo apt-get install qemu qemu-user

• Last thing to do is to use qemu with aapt2 instead of only aapt2

  mv $ANDROID_HOME/build-tools/28.0.1/aapt2 $ANDROID_HOME/build-tools/28.0.1/_aapt2

  Now move the aapt2 script from this repo into $ANDRID_HOME/build-tools/28.0.1/ and give it execution permission by

  chmod +x $ANDROID_HOME/build-tools/28.0.1/aapt2

  If you don't have a global ANDROID_HOME variable replace it with the corresponding path.
  Replace the build-tools version with yours!

  At some installations / in newer versions you also need to replace the aapt2 in ~/.gradle/caches/transforms-*/files-*/aapt2-*-linux.jar/*/aapt2-*-linux/ like above. This is a cache which means you need to try to build it and replace it afterwards.
  The * needs to be replaced with your specific versions (there should be only one at first).

• That's it. You can now build on 32bit Linux apps for Android.
  Your working folder can be deleted. There is no reference to it.

Further Information

I have tested this:

$ uname -a
Linux Generic 4.9.0-7-686-pae #1 SMP Debian 4.9.110-1 (2018-07-05) i686 GNU/Linux

$ qemu-x86_64 -version
qemu-x86_64 version 2.8.1(Debian 1:2.8+dfsg-6+deb9u4)
Copyright (c) 2003-2016 Fabrice Bellard and the QEMU Project developers

Maybe it also works on other distro than Debian.
Currently I can't test more than pure Debian.