Borgbackup not found

Hey everyone.
I just received hardware to build a raid for backup storage connected to the MOX via USB.
After troubleshooting some performance issues (that are hopefully solved now by adding an additional power supply) i finally got the raid assembled and mounted and tried to write a backup of a device on my LAN to it via borgbackup. However i realized that borg is not installed on the router and also not available on the repos.
That surprises me because

  1. i thought i had already installed borg on the Mox for testing purposes (although i may have done a fresh install of the device since then)
  2. borgbackup is available upstream in openwrt

Steps to reproduce:

opkg update
opkg install borgbackup

returns

 * opkg_install_cmd: Cannot install package borgbackup.

Is borg not available on turrisOS? Or is it just temporarily absent due to some build failure? (First would mean iā€™d misrember about having it installed already)

I checked the package list with my Omnia and BorgBackup is not present.