Alongside the release of Android 8.0 Oreo, Google unveiled Project Treble: a major rearchitecting in the way the Android OS framework and the vendor HALs and Linux kernel communicate. Treble is a major initiative designed to reduce Android platform version and security patch fragmentation, and all Android-branded devices launching with Android Pie are required to support Project Treble. OEMs and vendors test Treble compatibility by booting a Generic System Image (GSI)—a pure stock build of Android from AOSP—and passing the Vendor Test Suite (VTS) and Compatibility Test Suite-on-Generic System Image (CTS-on-GSI). The GSI has proven useful in not only allowing software engineers working for OEMs test Treble compatibility, but it has also opened the door for a large custom ROM community on XDA. For the Android Q release, Google wants to make GSIs useful for another group: app developers. Since the first stable release and source code drop of any given Android platform release usually comes in August, developers who would want to test the next Android release on a real device typically need access to a Google smartphone if they don’t want to wait for the update to reach their own ha...