Paul Sadauskas

It's entirely possible. Maybe Ruby in 2015 couldn't detect this problem so just returned an empty string, and modern Ruby IO notices somehow and is able to raise the IOError.

> Not only that, when no payload giving, mutating will actually raise an error: Right, I mentioned that in my commit message. I didn't want to make the change for...

I've rebased this branch with the devtools changes on master.

@solnic Sure, I can split this into two PRs, no problem. My reasoning behind rescuing `Exception` rather than `StandardError` is that in the situation where you're instrumenting some code that...

 I copied the unicode sequence from here: https://emojipedia.org/rainbow-flag/ First cat is just that emoji in a text file ten times. Second is the emoji + space ten times Third...

i3 has this as well, they call it "stacked" or "tabbed" https://i3wm.org/docs/userguide.html#_changing_the_container_layout