Lone_Wolf [1] filed a deletion request for mesa-transform-feedback-git [2]:

The patches added in this package have been present in mesa trunk master and stable versions for a long time now.

In my opinion this package no longer serves a purpose.

[1] https://aur.archlinux.org/account/Lone_Wolf/ [2] https://aur.archlinux.org/pkgbase/mesa-transform-feedback-git/