If i'm correct for NIX, all configuration is in lisp.
Question : What is the added value as compared to plain-FreeBSD?
I used Nixos for a while,
i think its own language rather lisp
someone described the nix language as being the love child of haskell and bash
The reason i stopped using nix is because the project doesnt update the documentation straight away
when they change how things work
So you have a config setup then it suddenly stops working
and then you have to look on the nix forum to try and find how to fix it
Trying to google for nixos information is a nightmare you get very few results
the issue is you might have software that has a bug and you have a simple fix that works on linux and unix
but you cant apply the fix to the nix version and you have to spend hours if not days
trying to find the nix fix for something that should take 5 minute to fix
also it doesnt follow the standard unix or linux file structure
it only has /bin/sh for scripts
which means you have to change all the shebangs in your non sh scripts like awk
or any other language because the standard file path for the binaries doesnt exist
nix has a main config file which defines how the system is set up
and you can specify a list of applications to install in that file
but then it has to rebuild the whole system every time you update an application
so you have to use another program called home-manager which has its own config files
to specify a list of applications to install
and then your home-manager config stops working because they have changed the syntax
so you then have to spend more time rewriting the config with the new syntax
at which point you begin to question why you are using it all
nix is basically a walled garden