I fought with this a few months ago when I did my own clone of gcc svn. My bad for only discussing this on #git at the time. Should have put this to the list as well.
If anyone recalls my report was something along the lines of git gc --aggressive explodes pack size. git repack -a -d --depth=100 --window=100 produced a ~550MB packfile immediately afterwards a git gc --aggressive produces a 1.5G packfile. This was for all branches/tags, not just trunk like Daniel's repo. The best theory I had at the time was that the gc doesn't find as good deltas or doesn't allow the same delta chain depth and so generates a new object in the pack, rather the reusing a good delta it already has in the well-packed pack. Cheers, Harvey
