[pacman-dev] Any final changes?

[Que Quotion]

What's the status on making BUILDENV extendable?

I've been using pacman-buildenv_ext-git very successfully for quite some 
time now.

https://aur.archlinux.org/cgit/aur.git/tree/buildenv_ext.patch?h=pacman-buildenv_ext-git

pacman-buildenv_ext-git can even be used to build packages with pgo, 
graphite, and lto in a "clean" chroot. I do this very often, it works 
(so long as the software being packaged itself can be safely optimized 
in those ways).