There are at least three non non-official packages for git-annex in the Arch Linux User Repository. Any of these may be installed manually per [AUR guidelines](https://wiki.archlinux.org/index.php/AUR_User_Guidelines#Installing_packages) or using a wrapper such as [`yaourt`](https://wiki.archlinux.org/index.php/yaourt) shown below.
2. A development package is available at [git-annex-git](https://aur.archlinux.org/packages/git-annex-git/) that functions similarly to the source package but builds directly from the HEAD of the git repository rather that the last official release.