variant symlinks (was Re: Anybody working on removing sendmail from base?)

[Matthew Dillon]

    The critical scenario for which 47 different versions of something might
    be needed is if you install 200 different ports which happen to depend
    on 47 different versions of, say, a patricular library.

    Basically the trade-off is:

    (1) Either you upgrade a port and break half the other ports that depend on
        that port, which is how FreeBSD works now.

		or

    (2) You upgrade a port, making a new version available, without breaking
	half the other ports that depend on the port you upgraded because those
	other ports can still be allowed to depend on an older version of the
	port.... which means that multiple versions of the dependant port
	have to remain in the system.

    Now, reasonably and obviously, one would want to also upgrade all the
    dependant ports.  Realistically however the process of upgrading dependant
    ports to use the new version of some dependancy can take weeks or months
    depending on the complexity of the ports involved.  

    Consider, for example, what happens when one tries to upgrade libpng.
    Seems simple enough, right?  But there are hundreds of ports which depend
    on libpng, including openoffice.  Suddenly upgrading libpng is not so
    simple.

    So we have a classic convenience/space tradeoff here, and I personally
    far prefer the convenience of being able to upgrade my system without
    breaking half my ports.

						-Matt