Dependency problem in the yum update FC3->FC4 chain

[Michael Wiktowy]

Greetings all,
I recently did a yum upgrade from FC3->FC4 (FC4 gets rid of a ton of
little annoyances that I had in FC3, BTW! Good work!)
I know that this is not an "officially supported" upgrade path but it is
a good way to test the integrity of dependencies and it did work ...
eventually.

I tried to be smart about it and update just yum first after installing
the fedora-release with a "yum update yum" (which consequently brings in
all the new yum dependencies and the packages that rely on those, &c,
&c.) This made sense to me since a new updater should handle the rest of
the upgrade better than the old one ... or so I thought. Apparently I
was too smart for my own good.

Due to a dependency problem, a new libxml2 didn't get pulled in, a
required python module didn't get loaded and yum wouldn't run anymore.
It wasn't until that moment that I realized how much I had grown to
depend on yum's excellent dependency resolution. It is kind of a PITA to
track down what I needed manually. But I did (with the help of google
and a previous bugzilla entry guiding me to run the yummain python
script directly to get the debug info directly rather than it getting
gobbled up in the wrapper. Forcing the new libxml2 in did the trick and
a simple "yum upgrade" did the trick after that.

Ironically enough, had I just left well enough alone and did a simple
"yum update" to get everything at once, everything would have worked out
fine.

All of that to ask the following ...
Is it worth it for me to track down the exact place where this
dependency problem occurs and give details in a bugzilla report? Or is
it going to be met with a "This method of upgrading is not supported ...
use anaconda next time, you crazy git! ->RESOLVED(Luser error)"? Is {the
ability to cleanly yum between releases} and {the yum upgrade path be
"officially supported"} future goals for the Fedora Project?

/Mike