Is there any way to have part of my build run on OS X and part of my build run on Linux?
Travis-ci supports this: https://docs.travis-ci.com/user/multi-os/#Example-Multi-OS-Build-Matrix using built matrices, but there is currently no native build matrices for circle-ci: Build matrix.
This feature is of interest for me when building a react-native project. I would like to build / run the IOS app on OSX, and the the Android part on Linux. Ideally I would also run any pure JS tests on Linux.