Artix appears to have a script for this which appears to be exactly what one wants to build in a clean chroot.
The Arch wiki appears to be not the best source now, sorry about that.
$ pacman -Ql artools-pkg
artools-pkg /usr/bin/mkchrootpkg
Usage: mkchrootpkg [options] -r <chrootdir> [--] [makepkg args]
Run this script in a PKGBUILD dir to build a package inside a
clean chroot. Arguments passed to this script after the
end-of-options marker (--) will be passed to makepkg.
The chroot dir consists of the following directories:
<chrootdir>/{root, copy} but only "root" is required
by default. The working copy will be created as needed
The chroot 'root' directory must be created via the following
command:
mkchroot <chrootdir>/root base-devel
This script reads {SRC,SRCPKG,PKG,LOG}DEST, MAKEFLAGS and PACKAGER
from makepkg.conf(5), if those variables are not part of the
environment.
Default makepkg args: --syncdeps --noconfirm --log --holdver --skipinteg
Flags:
-h This help
-c Clean the chroot before building
-d <dir> Bind directory into build chroot as read-write
-D <dir> Bind directory into build chroot as read-only
-u Update the working copy of the chroot before building
This is useful for rebuilds without dirtying the pristine
chroot
-r <dir> The chroot dir to use
-I <pkg> Install a package into the working copy of the chroot
-l <copy> The directory to use as the working copy of the chroot
Useful for maintaining multiple copies
Default: sol
-n Run namcap on the package
-C Run checkpkg on the package
-N Disable check() function
-T Build in a temporary directory
-U Run makepkg as a specified user
The last time I looked at the artools-pkg scripts was quite a while ago and I missed this one.