- cross-posted to:
- linux@programming.dev
- cross-posted to:
- linux@programming.dev
One aspect of Guix I found to be really fascinating: That there is basically no conceptual difference between defining a package as a private build script, and using a package as part of the system.
Let me explain: Say you wrote a little program in Python which uses a C library (or a Rust library with C ABI) which is in the distribution. Then, in Guix you would put that librarie’s name and needed version into a manifest.scm
file which lists your dependency, and makes it available if you run guix shell
in that folder. It does not matter whether you run the full Guix System, or just use Guix as s package manager.
Now, if you want to install your little python program as part of your system, you’ll write an install script or package definition, which is nothing else than a litle piece of Scheme code which contains the name of your program, your dependency, and the information needed to call python’s build tool.
The point I am making is now that the only thing which is different between your local package and a distributed package in Guix is that distributed packages are package definitions hosted in public git repos, called ‘channels’. So, if you put your package’s source into a github or codeberg repo, and the package definition into another repo, you now have published a package which is a part of Guix (in your own channel). Anybody who wants to install and run your package just needs your channel’s URL and the packages name. It is a fully decentral system.
In short, in Guix you have built-in something like Arch’s AUR, just in a much more elegant and clean manner - and in a fully decentralized way.
I wouldn’t call that an advantage for the average person. Nix is far nicer to work with. Some Lispers might disagree, but I, for one, can’t exactly see the beauty in trying to turn Scheme into a configuration language with macros and hacks. Also Guix puts Scheme everywhere, things you can do with plain old Bash in Nix, you’ll have to all do in Scheme in Guix, so there is a much steeper learning curve.
Well, Nix language is also full of hacks, idiosyncrasies and stupid decisions. I say that as someone who’s writing it “professionally”, i.e. as part of my job. Scheme is way less “unexpected”. But there are other parts of Guix which are pretty weird or just bad, like the “channels”/“pins” management situation.
Bash is not a advantage, it’s a disadvantage
You prefer:
over:
postInstall = '' rm $out/lib/basic-server $out/lib/helloworld $out/lib/postcollector ''
?
Bash code should definitely be
rm -f "$out"/lib/{basic-server,helloworld,postcollector}
Yes, having programmed bash and its predecessors for 30 years and several lisps (Clojure, Racket, Guile, a little SBCL) in the last 15 years, I very much prefer the Scheme version in this place.
Why?
'echo a; rm -rf /etc/*'
.(And don’t get me wrong, Unix shells are great if you want to save on extra keys pressed in a terminal session. But there are reasons that the shell languages are not often used in larger programs.)
I agree with your overall point, that having a single consistent functional language for package descriptions and build scripts is a great thing, and that bash is awful, but your reasoning is somewhat flawed. The main drawbacks of bash are somewhat rectified in Nix because bash is very much contained/sandboxed, which prevents arbitrary damage to the system, and there are some nice defaults in stdenv too.
Nix also supports multiple outputs (in fact this is where the concept of outputs in Guix came from)
You could also do that with Nix in an easier and more declarative fashion, either by adding a comment, or by doing this:
Bash is just two double quotes away from doing this too. See code above for an example
Bash also handles Unicode well
Nixpkgs stdenv sets
set -eu
which has a similar effect. If that code fails, the entire build will fail too.This is also really quite easy to rectify in bash, see code above.
Scheme is a minimalistic Lisp dialect, and macros are central in Lisp. For example, they allow for both conditional evaluation (“if” is a macro, or more precisely, a “special form” that is used in other conditionals), and for delayed evaluation at run time, which matches a bit Nix being lazy.
Also, Scheme is designed as a not strictly but mostly functional language, favouring side-effect free functions, which matches well with the declarative task which is package definitions.
bash, in contrary, is not side-effect-free, it modifies its environment, and this is very much not desired in a functional package manager: it is at the core that package declarations are side-effect-free.
And Emacs shows that Lisp written in a declarative style is a superb configuration language. (There is now even a project to use a Scheme, Steel Scheme, to configure helix, a programmers text editor which has many many features stemming from vim!).