I really tried making a derrivation for for the nomachine server, but it consists of a wrapper script in bash which for some reason is very long and complicated, this script calls a binary which required some libraries which were missing in the NixOS repo, and everyting assumed the program was installed in /opt/something. Then I tried steam-run, but the program just segfaulted on me when I tried. This is where I reckoned investing more time was not worth it.
On Arch I just do `yay -S nomachine` and call it a day.
But I really believe that someday the NixOS community will catch up, but currently it is not for me, since sometimes I want to get stuff done and not tinker with my system.