Ionic2 RC0 painfully slow update on save

After update to rc0 in ionic server, each save on my code editor do painfully refresh on browser.

On the log, it usually says:
bundle dev update finished in 43.44 s

Sometimes it just go into something like this:
<— JS stacktrace —>
==== JS stack trace =========================================
Security context: 0x274b3f8b4629

And it takes forever that I have quite and re-type ionic serve to pull everything backup…

It’s related to this issue