Earlier this year, Motorola released a special Android Go version of its lowest-end phone, the Moto E5 Play. It uses Google's Android Go platform, and is only available in a handful of European and Latin American countries. The phone might start to receive custom ROMs though, now that Motorola has released the kernel source code.
For those unfamiliar, the kernel source code allows developers to more easily create custom ROMs and recoveries for a certain phone. The package is now available from GitHub, and the "pettyl" codename confirms it's for the Android Go edition. You can download the source code at the link below.