Android 64-bit support
The next stable release of Defold (1.2.153) we will add Android 64-bit support. In the editor Android bundle dialog there are checkboxes for which architectures you want to include in your bundle, 32-bit (armv7) and 64-bit (arm64). For Bob, use the flag --architectures=armv7-android,arm64-android. You can of course choose to bundle separately for either architecture as well.
If you want to try it out the new architecture it is available in the Defold Beta 1.2.153 released yesterday:
- macOS: http://d.defold.com/archive/238152e93fe315c1f2b6a3d4050972f40c86de6b/beta/editor2/Defold-x86_64-darwin.dmg
- Windows: http://d.defold.com/archive/238152e93fe315c1f2b6a3d4050972f40c86de6b/beta/editor2/Defold-x86_64-win32.zip
- Linux:
http://d.defold.com/editor2/238152e93fe315c1f2b6a3d4050972f40c86de6b/editor2/Defold-x86_64-linux.zip
NOTE This should be seen as a temporary editor installation since it will not receive updates via the regular channels. Install it parallel to your current Defold installation rather than replace it.
Extension authors
If you are maintaining a native extension you might want to add support for arm64-android in your extension manifests and make sure they work as intended.
Use extension server https://build-stage.defold.com to build extensions targeting Once the we do the stable release we will release a new live extender server as well with this support.arm64-android.
EDIT: That build server is internal to us, we use it to test new versions before we release new versions. So you cannot test using that 
/Mathias