After I thought I had a decent script for figuring out what packages Anaconda would install from a Fedora 10 DVD, I decided to test it against reality. Reality made the script cry like a little girl, so it was back to the drawing board.

The problem, simply put, was that I had over-estimated the internal consistency of the data. Here’s what I learned in the process of producing a 100% match between my script and an actual default install of Fedora 10:

1. Packages listed in comps.xml don't necessarily exist, even if they're marked mandatory (like iprutils).
2. Conditional packages in comps.xml often depend on packages that are not themselves listed, but get included during dependency resolution (all of the OpenOffice language packs, for instance).
3. Packages often require themselves (more than two-thirds of perl's requirements are met by... perl).
4. Some packages specify a requirement for files installed by a package rather than features provided by that package (such as /usr/bin/perl; in an amusing note, this file is required by, but not a feature provided by, perl).
5. A few packages require files that are not installed by any package, and that's not considered an error.
6. It's not unusual for multiple packages to satisfy the same requirement, and when they do, Anaconda chooses the one with the shortest name. Seriously.
7. ...unless it's obsoleted by the other one, as in the case of the synaptics driver.
8. RPM doesn't actually care about all this nonsense; when it wants to know what libraries a package depends on, it opens it up and runs ldd on the contents.
9. This is required exactly once during a default Fedora 10 install, to discover the fact that totem-mozplugin requires mozplugger. I had to fake that one.

At some point, this knowledge will be put to use upgrading my EEE PC from Fedora 9, but now that I can declare victory and stop tinkering with the script for a while, I’m going to go finish the Japanese novel I’m currently working my way through (60 pages down, 200 to go).