/ must be on a partition or LV that will be formatted. Reusing an existing / is not allowed.

[Chris Lumens]

> If the installer is sufficiently aggressive about warning clueless
> users to let it reformat / unless they really, really know what
> they're doing, then people who choose still not to reformat / and
> end up with a broken system have only themselves to blame, and their
> bugs can justifiably and quickly be closed NOTABUG.

Such bugs will almost always get reopened with a followup of "well,
anaconda should not have let me do that if it wasn't going to work".
And they're right.

> I really don't buy the argument that this is necessary to make
> anaconda robust. As long as anaconda can detect the right options to
> put in /etc/fstab for the preformatted / partition, anything else it
> needs to be able to do to install on top of a preexisting /, it
> should be able to do. If there are specific issues that it needs to
> handle that it doesn't handle properly, then fix those issues.

I think this is completely unreasonable to expect.  You think we should
be able to take a /, which might have the leftovers of previous failed
installations, do an install on top of that without removing what was
there, and the result should be a fully functional Fedora installation?
There will never be an end to the stream of bugs generated by allowing
something like that, and we have far more effective ways of spending our
limited time - like making sure we can do partitioning correctly.

> This strikes me as very much throwing out the baby with the bathwater.

Well for kickstart users who want to do this intentionally, they can
still continue to do so (though, be careful).

- Chris