There is a non-official source package for git-annex in AUR.
You can then build it yourself or use a wrapper for AUR such as yaourt:
$ yaourt -Sy git-annex
I'm told the AUR has some dependency problems currently. If it doesn't work, you can just use cabal:
pacman -S git rsync curl wget gpg openssh cabal-install cabal install git-annex --bindir=$HOME/bin
I am experiencing a weird issue with any install I've had on this one (and only) ArchLinux machine: all of aur/git-annex 4.20130516-1, aur/git-annex-bin-4.20130909-1, aur/git-annex-standalone-4.20130909-1 and a Cabal install just stall when trying to create the initial Git annex repo in the webapp.
When started, it offers me to create the annex in ~/annex/ or ~/Desktop/annex/, where ~ gets turned into /home/USER when I press “Make repository”, but nothing else happens. This is regardless of if that repo exists when I try to create it or start the webapp.
If I start the webapp from an existing annex (now in ~/annex), it seems to work a bit better, but any other remote (SSH) server that I try to add fails. I just get a fleeting Bootstrap message box when I click “Check this server”, and nothing in the logs of eithr git annex webapp or the ssh logs of the server.
Any idea? Where should I look for more debug information? .
Done [0]. Not much debug output, unfortunately...
[0] http://git-annex.branchable.com/bugs/Assistant_stalls_when_adding47creating_repo_on_ArchLinux/?updated