Improve your maven android build speed

Here’s a nice way of shaving around 10 seconds off your average maven builds total time when building Scala Android applications.

You know the part when you need to unpack everything to have ProGuard go through all your classes to remove that extra fat. Well, even if you make a lot of changes to your code, most of the time is spent unpacking the libraries (Scala and Android mainly). And these libraries don’t change that often. So after you’ve done it once, and they have already been unpacked to your target directory, why do it again? Well, someone figured that out and now it’s added to maven-android-plugin in version 2.9.0-beta-5, so switch to that from 2.8.4 which is what you are probably using.

Then all you need to do is add the line:

<lazyLibraryUnpack>true</lazyLibraryUnpack>

under the <configuration> of your maven-android-plugin.

If this causes force closes on your device/emulator, check that your ProGuard settings are not too aggressive.