Outstanding problems: * Cross-compiling our Python virtualenv packages is going to be involved. Maybe we can use https://github.com/benfogle/crossenv. * The therubyracer gem we use (0.12.3, latest) (0.12.3) in the api server depends on libv8 (~> 22.214.171.124) which is a version so old it only compiles on x86. Newer versions of libv8 compile on aarch64 too. We should migrate to `mini_racer` apparently.