Quicklisp To Nix

So you’ve got a Common Lisp project that you want to build in Nix? ql2nix can help! ql2nix will help you produce a nix expression that builds a Quicklisp bundle that contains the Common Lisp dependencies of your project.

Building

The preferred way to build ql2nix is with Nix, of course! ql2nix includes a default.nix that builds ql2nix. Just run nix-build!

nix-build

ql2nix is also a valid ASDF system and it is set up to output an executable. So, all you need to do is get ASDF to perform the program-op on "ql2nix". Something like this!

sbcl --eval '(require :asdf)' \
     --eval '(let ((asdf:*central-registry* (cons (truename ".") asdf:*central-registry*)))
               (asdf:oos (quote asdf:program-op) "ql2nix"))'

ASDF will save the executable in the usual output location – usually somewhere in $HOME/.cache/common-lisp/.

Usage

ql2nix [--quicklisp-setup path/to/quicklisp/setup.lisp] [--project-dir PATH] [--] system...

ql2nix works by loading the named systems with ql:quickload. Any system that ASDF touches gets marked. If that system is provided by your Quicklisp installation then ql2nix will include it in the closure.

If ql2nix wasn’t built with Quicklisp already loaded then you must provide the path to Quicklisp’s setup.lisp via the --quicklisp-setup command line argument.

Any paths you specify with --project-dir will be included in ASDF’s source registry. Systems contained within those paths are not included in the closure that ql2nix produces.

There are two ways you can use ql2nix. You can either have ql2nix load your ASDF system and discover required dependencies automatically or you can pass in dependencies explicitly. Either way, you must run ql2nix in an environment where it can ql:quickload the systems that are named. So, if a package depends on a native library then that native library must be available in the environment when you run ql2nix. For example…

nix-shell -p someNativeDependency # if you have any!
# Automatic dependency discovery
ql2nix --quicklisp-setup ~/quicklisp/setup.lisp --project-dir path/to/your/source/ your-system-name
# Explicit dependencies
ql2nix --quicklisp-setup ~/quicklisp/setup.lisp systems-you depend-on-go here

Either way, ql2nix will output a file named qlDist.nix. This file describes the transitive closure of Quicklisp systems that were touched while loading the systems specified on the command line. qlDist.nix can be combined with the provided mkNixlispBundle.nix to produce a Nix derivation that contains the transitive closure of systems described by qlDist.nix.

If you’re already using Nixpkgs’s clwrapper, then using mkNixlispBundle is trivial. Simply include the derivation it returns in your buildInputs. clwrapper will ensure that all of the closure’s systems are included in ASDF’s source registry. For example,

{ pkgs ? import <nixpkgs> {} }:

with (import (fetchFromGitHub {
  owner = "SquircleSpace"
  repo = "ql2nix";
  rev = "...";
  sha256 = "...";
}) { inherit pkgs; });

let
  nixlispBundle = mkNixlispBundle ./qlDist.nix;
in
pkgs.stdenv.mkDerivation rec {
  name = "example";
  buildInputs = [ ql2nix nixlispBundle ];
  # ...
}

If you’re not using clwrapper, then you’ll need to LOAD the file at lib/common-lisp/bundle/bundle.lisp. This file will configure ASDF so that the closure’s systems are included in ASDF’s source registry.

As mentioned above, you need to use mkNixlispBundle to leverage the qlDist.nix file produced by ql2nix. Until Nixpkgs includes mkNixlispBundle, you’ll need to embed it within your project. ql2nix will helpfully write out the supporting Nix expressions alongside qlDist.nix if you pass in the --nixlisp-lib flag.