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Changes between Version 3 and Version 4 of Ticket #198

v3	v4
6	6	* "cabal install world" (upgrades only "interesting" packages and any required upgrades)
7	7	* "cabal install foo" (upgrades foo and any required upgrades from foo)
8		* "cabal install foo --deep" (upgrades foo and all its dependencies whether required or not)
	8	* "cabal install foo --deep" (upgrades foo and all its dependencies whether required or not)
9	9
10	10	= Definitions =
11	11	* '''Interesting packages''' are packages that a user specifically requests, rather than a package that's installed because of a dependency.
	12	* If someone specifies a version number, is that version itself "interesting"?
12	13	* '''Obsolete packages''' are packages which were installed as a dependency on an interesting package, but are no longer depended on by any interesting package.
13	14	* '''required upgrades''' - if the new version of foo requires a new version of Bar, then we are required to upgrade bar.
	15
	16	= Niggly Questions =
	17	* Rebuilding packages
	18	* If Foo depends on Bar, and Bar gets upgraded for whatever reason, should we rebuild Foo, even if it wasn't upgraded, so it uses the new Bar?
	19	* This obviously could require rebuilding all the way up the dependency tree.
	20	* Deleting packages:
	21	* Do we delete obsolete packages?
	22	* If we rebuild packages as above, do we delete old versions of uninteresting packages, considering them obsolete?
	23	* Do we delete old versions of interesting packages?
14	24
15	25	= behavior of "install foo" =