Don't use packer for installing non-AUR packages

The problem is the breakage that can develop between fully updated Arch repositories and the mostly much slower reacting AUR packages.
So for your own good it is useful to get aware what is from AUR and not
And not mixing the two in your mind as if they are packages of equal quality.
You should go for the official package unless you have strong reasons to use an AUR package and be critical to use elementary packages like kernel builds from AUR sources.
Always install an official, non-AUR package with pacman and consider a system update always when installing a package.
When thinking about installing an important or bigger new package always be conscious of what dependencies it has and consider if it is not a good moment to update first with
pacman -Syyu
(and not packer -Syyu!!) and then install your new package with pacman.
Remember that if you are curious and only do pacman -Syy, it is risky to install only a package and not do a total system upgrade as that might lead to mixing different dependencies that are not in sync ( the update of one package also needs the update of another package).
Start using your system and when everything is OK after a reboot, only then do packer -Su.
At least this is the way I manage to avoid breakage on my system for already a rather long time.