This is like saying a user who clone a random git repo is not to blame and git-scm should do more to prevent cloning of malicious repos. If it is not official, it is your job to review, if you dont like it, use iOS instead of Arch Linux.

If you crash your car, you are liable for the accident. If you aren't ready for that, take the bus.

More power = more responsibility

As an arch user, I would always skim the PKGBUILD file of AUR packages to see if they install the software they claim to install from official sources and if there's something obviously fishy.

An archlinux package build file is just a shell script. It's pretty easy to take a look and see if all the manifest info is right and it doesn't do more than ./configure; make; make install DESTDIR=$PKG or whatever. If you're building random software using random instructions from the internet and don't make sure they're not malicious, you only have yourself to blame when you catch something. Actually reading through the source files for vulns is something best left for automatic detection, checking the build script is basic.

> If it's a binary package, how do you do that?

You find one that builds from source, or you still review PKGBUILD and friends and lean more on evaluating the reputation of upstream and its maintainers, or you simply decide never to install binary packages. Your policy is yours to decide.

> Putting this on users is not a tenable solution.

The alternative would be to not have an AUR. Archlinux has official package repos where packages are vetted. The AUR (Arch User Repository) is not that. The AUR is there to provide greater variety of software than the official repos can, and it does that by not incurring the cost of being individually maintained by volunteer Arch staff and developers. It needs to not incur that cost for it to exist, otherwise it'd just be the official repos. It's like github, but limited to repos with PKGBUILDs.

Ask an LLM to assess the package and do a web search for you. Nobody is installing tens of packages a day, you can take a few minutes to consider what you are installing. This isn't blaming the user, it's basic digital hygiene.

It’s free lines of code on the internet that you are going out of your way to run on your own machine.

Lets take two real and random examples, and I'll share what I'd look for:

First, very easy one, we want to install Brave, so we find https://aur.archlinux.org/packages/brave-bin. All the dependencies are in the official repos already, so those we trust already, you open the downloaded PKGBUILD and you find it's downloading a binary from github.com/brave, you check to see it's the official GitHub profile/organization that you expect. Quickly scan prepare/package for anything out of place, like downloading more files not defined in "source" or whatever. In this case, "suid sandbox" stuff should make you investigate closer so you understand what that stuff does, many things related to Chrome has things like that. That AUR package also has a brave-bin.sh, so a look through that would make sense. AFAIK, everything checks out, this is literally just downloading the official release from GitHub, and extracts it into the right place, so if you trust the GitHub org/user, you can trust the PKGBUILD. The PKGBUILD also seems to be officially maintained by Brave themselves, so probably already there you can verify the AUR user and be done if you feel lax.

Second example is unofficial package, https://aur.archlinux.org/packages/lmstudio-bin, maintained by noureddinex and created by MadGoat, neither which seem official at a glance. Read through the comments to see if anyone else flagged anything, seems fine so again go read the source of the package and the PKGBUILD. PKGBUILD seems standard, downloads something from "installers.lmstudio.ai" so first thing to check is if that's actually the official website, so use search engine to find official website, copy the URL of the download, verify it's the same. In this case, lmstudio.ai is the real website, but download URL on website ends up being "https://lmstudio.ai/download/latest/linux/x64" in the HTML/DOM, so use "curl -v -L $URL" to see redirects, and then we've confirmed installers.lmstudio.ai is actually what they use for official releases. Read through "prepare" and "package", both seem standard and fine, then look through the rest of the files, all of them seem fine, mostly maintenance scripts for the AUR package itself. Package seems fine as a whole, and we could install it, if we're willing to review it again on upgrades in the future.

This is basically all you have to do. Writing what I did while doing it, made each "review" take maybe 5-10 minutes, and it isn't harder than that, regardless who the user is. You just need to know what to look for, and think how you'd "officially" install it anyways. And if what the PKGBUILD differs from what you'd imagine an "official install" would do, investigate if it makes sense and if not, don't install the package, maybe leave a comment for others in AUR to dive deeper.