For the record, pacman already supports diffs like this, but Arch has not set up official mirrors that host binary diffs instead of full packages. There has bee

For the record, pacman already supports diffs like this, but Arch has not set up official mirrors that host binary diffs instead of full packages. There has been at least third-party repository that hosted diffs for ArchLinux packages. I too think this should be a much higher priority than it is for many. Fedora has had (non-default) support for this for years, but that's about it. You shouldn't worry so much about diffing against previous versions -- if you diff against the last two versions, it won't use much extra disk space, and the worst case scenario is that someone has to download the full package as a fallback, which everyone has to do now.