Any options to replace GNU coreutils on Linux?
busybox the favorite of Embedded Linux systems.
BusyBox combines tiny versions of many common UNIX utilities into a single small executable. It provides replacements for most of the utilities you usually find in GNU fileutils, shellutils, etc. The utilities in BusyBox generally have fewer options than their full-featured GNU cousins; however, the options that are included provide the expected functionality and behave very much like their GNU counterparts. BusyBox provides a fairly complete environment for any small or embedded system.
BusyBox has been written with size-optimization and limited resources in mind. It is also extremely modular so you can easily include or exclude commands (or features) at compile time. This makes it easy to customize your embedded systems. To create a working system, just add some device nodes in /dev, a few configuration files in /etc, and a Linux kernel.
You can pretty much make any coreutil name a link to the busybox binary and it will work. you can also run busybox <command> and it will work. Example: if you're on Gentoo and haven't installed your vi yet, you can run busybox vi filename and you'll be in vi. It's
Arch Linux - community/busybox
Gentoo Linux - sys-apps/busybox
Alpine Linux - based on BusyBox and uClibc, here's an overview
This is an older topic, I realize. However, this solution was never mentioned and comes up relatively high on google for "Linux with bsd userland".
There's another solution: heirloom. I know it works on Arch, and it's packaged in the AUR (look at gnu2sysv, for instance). This will replace Arch's coreutils package and provide the heirloom equivalents. You can read about the whole thing on arch's wiki: https://wiki.archlinux.org/index.php/Base2heirloom
Check out uutils.
This is a cross platform implementation of the GNU coreutils that is written in Rust. It is MIT licensed. At the time of writing this answer it is not 100℅ complete (missing some crucial ones like ls and cp), but many other ones are done.