Usage in NixOS?

[Kreyren]

I would characterize NixOS as scientific linux distribution focused on reproducibility which uses a custom data-driven functional programming language for it's workflow such as shown example hello-world package:

# This is nixlang
{ callPackage
, lib
, stdenv
, fetchurl
, nixos
, testers
, hello
}:

stdenv.mkDerivation (finalAttrs: {
  pname = "hello";
  version = "2.12.1";

  src = fetchurl {
    url = "mirror://gnu/hello/hello-${finalAttrs.version}.tar.gz";
    sha256 = "sha256-jZkUKv2SV28wsM18tCqNxoCZmLxdYH2Idh9RLibH2yA=";
  };

  doCheck = true;

  passthru.tests = {
    version = testers.testVersion { package = hello; };

    invariant-under-noXlibs =
      testers.testEqualDerivation
        "hello must not be rebuilt when environment.noXlibs is set."
        hello
        (nixos { environment.noXlibs = true; }).pkgs.hello;
  };

  passthru.tests.run = callPackage ./test.nix { hello = finalAttrs.finalPackage; };

  meta = with lib; {
    description = "A program that produces a familiar, friendly greeting";
    longDescription = ''
      GNU Hello is a program that prints "Hello, world!" when you run it.
      It is fully customizable.
    '';
    homepage = "https://www.gnu.org/software/hello/manual/";
    changelog = "https://git.savannah.gnu.org/cgit/hello.git/plain/NEWS?h=v${finalAttrs.version}";
    license = licenses.gpl3Plus;
    maintainers = [ maintainers.eelco ];
    platforms = platforms.all;
  };
})

NOTE: passthru.tests* and doCheck should be ignored to keep the proof of concept simple

Which generates a "derivation":

"/nix/store/57677sld6ja212hkv1gh8bdm0amnk1hz-hello-2.12.1.drv": {
    "args": [
      "-e",
      "/nix/store/6xg259477c90a229xwmb53pdfkn6ig3g-default-builder.sh"
    ],
    "builder": "/nix/store/lf0wpjrj8yx4gsmw2s3xfl58ixmqk8qa-bash-5.2-p15/bin/bash",
    "env": {
      "__structuredAttrs": "",
      "buildInputs": "",
      "builder": "/nix/store/lf0wpjrj8yx4gsmw2s3xfl58ixmqk8qa-bash-5.2-p15/bin/bash",
      "cmakeFlags": "",
      "configureFlags": "",
      "depsBuildBuild": "",
      "depsBuildBuildPropagated": "",
      "depsBuildTarget": "",
      "depsBuildTargetPropagated": "",
      "depsHostHost": "",
      "depsHostHostPropagated": "",
      "depsTargetTarget": "",
      "depsTargetTargetPropagated": "",
      "doCheck": "1",
      "doInstallCheck": "",
      "mesonFlags": "",
      "name": "hello-2.12.1",
      "nativeBuildInputs": "",
      "out": "/nix/store/cg8a576pz2yfc1wbhxm1zy4x7lrk8pix-hello-2.12.1",
      "outputs": "out",
      "patches": "",
      "pname": "hello",
      "propagatedBuildInputs": "",
      "propagatedNativeBuildInputs": "",
      "src": "/nix/store/pa10z4ngm0g83kx9mssrqzz30s84vq7k-hello-2.12.1.tar.gz",
      "stdenv": "/nix/store/bbxdw4rgwwl3gnajri82yidr1nlsfskf-stdenv-linux",
      "strictDeps": "",
      "system": "x86_64-linux",
      "version": "2.12.1"
    },
    "inputDrvs": {
      "/nix/store/0m92zn8yv2z6zw29y60iwmzwwr05y0yl-stdenv-linux.drv": [
        "out"
      ],
      "/nix/store/3mj2s5v60nf60h1bmqkkayvvdsv483c8-hello-2.12.1.tar.gz.drv": [
        "out"
      ],
      "/nix/store/qqw8l23c7l4k2xkf3ab8z1354mq0jy8m-bash-5.2-p15.drv": [
        "out"
      ]
    },
    "inputSrcs": [
      "/nix/store/6xg259477c90a229xwmb53pdfkn6ig3g-default-builder.sh"
    ],
    "outputs": {
      "out": {
        "path": "/nix/store/cg8a576pz2yfc1wbhxm1zy4x7lrk8pix-hello-2.12.1"
      }
    },
    "system": "x86_64-linux"
  }
}

NOTE: The prefixes alike /nix/store/abcdef...-PACKAGE-VERSION/ are functions within the nixlang, the example should probably use a placeholder

Which the nix package manager uses to declare the build environment (declaring variables and dependencies) to then realize the package.

This is basically the minimal example of how NixOS works which to me seems similar in nature to the enso example of processing the advertiser data in california shown in the project introduction (https://www.youtube.com/watch?v=fQvWMoOjmQk&ab_channel=Enso) as in both case we are basically just manipulating a JSON data.

Could Enso be used instead of nixlang to declare packages for nix and if so how could that be declared in Enso assuming that we are only providing the following inputs:

1. Name -- hello
2. Version -- 2.12.5
3. Source -- mirror://gnu/hello/hello-2.12.5.tar.gz
4. Source checksum -- sha256-jZkUKv2SV28wsM18tCqNxoCZmLxdYH2Idh9RLibH2yA=
5. Homepage -- https://www.gnu.org/software/hello/manual/
6. Changelog -- https://git.savannah.gnu.org/cgit/hello.git/plain/NEWS?h=v2.12.5
7. License -- GPL3+
8. Maintainers -- eelco
9. Supported platforms -- platforms.all
10. Description -- A program that produces a familiar, friendly greeting
11. Long Description -- GNU Hello is a program that prints "Hello, world!" when you run it. It is fully customizable.

---

Additionally some packages require a special treatment which is often handled in nixlang by passing instructions to the Bash script interpretor e.g. gcc6 package https://github.com/NixOS/nixpkgs/blob/nixos-23.05/pkgs/build-support/cc-wrapper/default.nix#L546 which then generates a derivation with

...
"postFixup": "touch \"$out/nix-support/cc-cflags\"\ntouch \"$out/nix-support/cc-ldflags\"\nif [[ -f \"$bintools/nix-support/dynamic-linker\" ]]; then\n  ln -s \"$bintools/nix-support/dynamic-linker\" \"$out/nix-support\"\nfi\nif [[ -f \"$bintools/nix-support/dynamic-linker-m32\" ]]; then\n  ln -s \"$bintools/nix-support/dynamic-linker-m32\" \"$out/nix-support\"\nfi\ntouch \"$out/nix-support/libc-cflags\"\ntouch \"$out/nix-support/libc-ldflags\"\necho \"-B/nix/store/gqghjch4p1s69sv4mcjksb2kb65rwqjy-glibc-2.38-23/lib/\" >> $out/nix-support/libc-crt1-cflags\necho \"-idirafter /nix/store/x8lqlydsxbrwvf6p7v18gws8kn1xl37f-glibc-2.38-23-dev/include\" >> $out/nix-support/libc-cflags\nfor dir in \"/nix/store/5whhhqmj7z25pyb62rl38plwwvfpck0i-gcc-6.5.0\"/lib/gcc/*/*/include-fixed; do\n  echo '-idirafter' ${dir} >> $out/nix-support/libc-cflags\ndone\n\necho \"/nix/store/gqghjch4p1s69sv4mcjksb2kb65rwqjy-glibc-2.38-23\" > $out/nix-support/orig-libc\necho \"/nix/store/x8lqlydsxbrwvf6p7v18gws8kn1xl37f-glibc-2.38-23-dev\" > $out/nix-support/orig-libc-dev\ntouch \"$out/nix-support/libcxx-cxxflags\"\ntouch \"$out/nix-support/libcxx-ldflags\"\nif [ -e \"/nix/store/5h10nzggcrh4g3qgwjw2v2z2v76nxp4j-gcc-6.5.0-lib/lib64\" -a ! -L \"/nix/store/5h10nzggcrh4g3qgwjw2v2z2v76nxp4j-gcc-6.5.0-lib/lib64\" ]; then\n  ccLDFlags+=\" -L/nix/store/5h10nzggcrh4g3qgwjw2v2z2v76nxp4j-gcc-6.5.0-lib/lib64\"\n  ccCFlags+=\" -B/nix/store/5h10nzggcrh4g3qgwjw2v2z2v76nxp4j-gcc-6.5.0-lib/lib64\"\nfi\nccLDFlags+=\" -L/nix/store/5h10nzggcrh4g3qgwjw2v2z2v76nxp4j-gcc-6.5.0-lib/lib\"\nccCFlags+=\" -B/nix/store/5h10nzggcrh4g3qgwjw2v2z2v76nxp4j-gcc-6.5.0-lib/lib\"\n\necho \"$ccLDFlags\" >> $out/nix-support/cc-ldflags\necho \"$ccCFlags\" >> $out/nix-support/cc-cflags\nln -s /nix/store/jkyrpw9h8cdfkfkqjnpf3ns71196ns3h-gcc-6.5.0-man $man\nln -s /nix/store/98lg5v310hr7x7k0g2c9g3b3ax79l4sj-gcc-6.5.0-info $info\nexport hardening_unsupported_flags=\"fortify3\"\nfor flags in \"$out/nix-support\"/*flags*; do\n  substituteInPlace \"$flags\" --replace $'\\n' ' '\ndone\n\nsubstituteAll /nix/store/ji2yrl1na00bwav65hh1vr0nc0s1xzvz-add-flags.sh $out/nix-support/add-flags.sh\nsubstituteAll /nix/store/y7s34z2dkhvgjgjdb9zwm7zbzq1k0711-add-hardening.sh $out/nix-support/add-hardening.sh\nsubstituteAll /nix/store/kgcmpr4i443sdyszl1b7i4k86ddxbrwi-utils.bash $out/nix-support/utils.bash\n",
...

Could the same be handled in enso?