JS.alert doesn't work in 5.9 unless HTML DevTools is open

[TextMisadventures]

I'm not quite sure this is an actual Issue.

I sometimes use JS.alert for debugging, and it no longer works in the 5.9 build unless the HTML DevTools window is open.

I can't find any Core code that uses this, and everything else I tried with JS works fine.

[alexwarren]

This doesn't feel like something to worry about too much, I don't think games should really be using this anyway.