Github user takezoe commented on the issue:
https://github.com/apache/predictionio/pull/462
> Does --build-arg option solve it?
Using `--build-arg` is nice! But I mean it would be nice if we can create a
docker image on my working copy before commit and push something. But this is
my opinion. Don't mind if you don't need it.
> Just in case, I moved MySQL download process into pio_run.
Good idea. This solution can be applied to setup of native distributions.---
