I think the emscripten threads problem will eventually get fixed. In the mean time, I don't think there's a huge problem with using 1.8.7, but you might be able

I think the emscripten threads problem will eventually get fixed. In the mean time, I don't think there's a huge problem with using 1.8.7, but you might be able to improve it using the backports gem [1]. [1] https://github.com/marcandre/backports https://github.com/marcandre/backports