Future imports are not imports at all (the fact that they use the same syntax as imports is misleading IMO). They are tags that instruct the interpreter to turn on certain features only when interpreting the given file. They must appear before any statements in the file, and they take effect before interpretation of the file starts. You could argue that this constitutes an import side effect, but that's neither here nor there, and not helpful.
1. Initializing a point of sale printer, checking for errors, and raising exceptions if, say, it is out of paper? Let's say this is a cash drawer driver and the cash drawer connects through the printer, and if the printer is out of paper, the drawer won't open properly (this happens btw). I would call this a side effect as well as a separation of concerns violation btw. However it is not likely to be a visible change to other modules.
2. Check for the presence of a binary and if found, cache the path to it, perhaps instantiating another object to do so? Definitely a side effect there, but not publicly visible.
3. Initializing an external library's environment (as happened in this case)? Done wrong it crashes the system but I suspect the segfault was not intended. Again it isnt clear to me you have a publically visible side effect intended.
