Code review comment for ~ajorgens/cloud-init:pipe-cat

So... I spent a lot of time yesterday trying to use pty.openpty() to make a unit test for this, and I give up, at least for now. I'm unsure if the code is bad or if the unit test is impossible.

In Amazon Linux we're using the redirect_output thing to pipe everything through tee anyway, so this is likely a non-issue for us. If I feel ambitious or have a great idea how else to solve this I might do that some day, but for now I'm dropping it.