I agree that it is not reasonable to expect `.output` to behave any differently than it currently does; that would be way too complicated. The thing is, I don't think I have ever used `.output`, but I use `.once` regularly. And when you don't connect the two commands in your head, it is very easy to fall into the trap of assuming that `.once` will wait before actually running the named command. Clearly, that is what happened to me. (I _do_ know about pipes and what they do; so here is at least one data point suggesting it is not evident.) Here is one suggestion for an addition to the documentation: > The given command is started immediately. Beware of specifying a command that will try to interact with the terminal. This should provide sufficient warning for knowledgeable users. But perhaps it is too cryptic for less sophisticated users.