Why do we not place mezuzot on the doorways of sukkot? Given that the sukkah is supposed to function as a primary dwelling, it would seem to merit the inclusion of a mezuzah - especially if one were sleeping within it.
In the event that the reason has to do with its only being used for a temporary period of time, does the halakha change if a person decides to reside within their sukkah permanently? If they make such a decision, does the obligation to affix a mezuzah come into effect after thirty days or immediately?
(This is effectively two or three questions in one, but since the latter two hinge on the answer to the first I have included all three together. Obviously, I'm looking for sources.)