Hello Gisle, nice to see you here! :-)
There is currently no such "unix-emulating" package in SvarDOS. I think your best bet would be picking one of the solutions listed below, esp. "UXUTL" or the "Berkeley Utilities":
https://www.bttr-software.de/freesoft/unix.htm
I am not a GNU fan myself, but should any of these packages happen to be worthy in your experience, I can see to make a suitable *.svp package. That said, if your target is DosBox, then *.svp packages have probably no added value to you anyway (unless you use the SvarDOS package system with DosBox? That would be an interesting, albeit somewhat exotic setup).
Mateusz