Because I was looking at some fails, like the grouping tests, and I didn't see a Lucene issue that should have broken them, but it is extremely difficult to work out an 8 month old branch with multiple non rebase merge ups starting from zero history working with the branch.
There are also subjective choices you can make to do the upgrade, and I wanted to see what you actually had to drop or what tests had to be ignored if you just did a minimum job following Lucene’s Migrate document and CHANGES.txt. I didn't end up ignoring any tests, and I didn't drop preanalyzed field or Lucene native timeouts for example. That is much easier to do when you are familiar with all of the changes and work vs trying to jump in on a lot of work at the end of it with little context or experience with what all of the changes are. And now that you have merged up, I can easily diff the two branches and compare.
