installation with nix

[zoranbosnjak]

Please consider adding this project to the nix packages.

My intention is to use entangled to extract code snippets from markdown files as part of automated tests during nix-build process. The probem is that I can not use pip install under this scenario.

[claymorwan]

Yea that'd be nice, expecially since the previous haskell version had a flake.
I actually already packaged brei (i just add to change rich and argh's version to include the ones available in the nixpkgs), im struggling with repl-session tho since it uses uv as a build tool, which nix doesn't like

[claymorwan]

nvm i got repl-session to build, just need a way to use local packages as dependency for buildPythonPackage.dependencies so i can test the package before sending it, if anyone knows how to that'd be helpful

[claymorwan]

ok actually i don't even know if this can be in the nixpkgs yet cuz the depencies available in it doesn't satisfy the ones wanted by entangled-cli, brei and repl-session, and even with messing with the deps version i still somehow am missing mawk and doesn't satisfy version for argh

[jhidding]

Ok, mawk and argh are both old dependencies and will be removed in the next version. There's a test failing on Windows that holds me back a bit. I'm no expert in Nix packaging so contributions are welcome.

[claymorwan]

o well if mawk and argh get removed it'll be easier to package, but there's still a few dependencies where i'll need to tweak the required version a bit, at least until the nix packages for them are updated to match the required ones

[jhidding]

I'm slightly confused though: these packages you mention are all pure Python and there should be no issue at all getting them installed. Their development environment may depend on uv, but installing them doesn't. Both repl-session and brei are developed by me and are only tangential dependencies, but you could bundle them in a single derivation/flake (my Nix expert colleague tells me).

[claymorwan]

well when packaging a python package, all of it's python deps are from the nixpkgs as well and not directly from pypi, also know that when packaging them for nix u gotta build them, not just directly install them

i can build brei and repl-session just fine (the uv issue was just a little stupid thing i messed up), but since they need version that aren't on the nixpkgs i gotta manually change them to the ones availble
for example: brei needs rich v13.6.0, but the version of rich available on nixpkgs is v14.2.0, so unless there's a way to use older version of a dependency when making a nix package, i gotta manually change the required version of rich by brei to match v14.2.0

tho i gotta say im far to be a nix expert so please correct me if im wrong

[v1kko]

I have created nix flake(s) to support entangled #89, entangled/brei#13 and entangled/repl-session#1

The version changing is a bit of a pain, and needs to be synchronized across the three repositories (there's probably better options available) but this works for now,

If entangled is to be added to the nixpkgs repo I think it should first be able to run with the package versions available in nixpkgs (unstable).

[claymorwan]

o that's amazing, i'll try it as soon as it gets merged

[claymorwan]

quick question, what to i type in if i want to install it declaratively ? i tried inputs.entangled.packages.${pkgs.stdenv.hostPlatform.system}.entangled but it didn't work

[claymorwan]

also I'm getting this error when running nix run

$ nix run github:entangled/entangled.py
error:
       … while updating the lock file of flake 'github:entangled/entangled.py/3f9b0c9ac2bd8ca118865e728a3462c5b48eac76?narHash=sha256-yw2zHxdWrbAUZ65OzqQs10/7K3o%2BEuMUiNFSkoCxdj4%3D'

       error: cannot write modified lock file of flake 'github:entangled/entangled.py' (use '--no-write-lock-file' to ignore)

trying with --no-write-lock-file returns this

error:
       … while evaluating the attribute 'drvPath'
         at /nix/store/3cykcmnpiqdskv7sxkzcrn1x2lir4z5v-source/lib/customisation.nix:446:7:
          445|     // {
          446|       drvPath =
             |       ^
          447|         assert condition;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: Python version mismatch in 'python3.13-entangled-cli-2.4.2':

       The Python derivation 'python3.13-entangled-cli-2.4.2' depends on a Python derivation
       named 'python3.13-brei-0.2.4', but the two derivations use different versions
       of Python:

           'python3.13-entangled-cli-2.4.2' uses /nix/store/slhpx9glq7vl99bwi93bgrhn3syv98s1-python3-3.13.11
                    'python3.13-brei-0.2.4' uses /nix/store/qzc04a3npl70cyyy6flnnrb2ig3kayxm-python3-3.13.11

       Possible solutions:

         * If 'python3.13-brei-0.2.4' is a Python library, change the reference to 'python3.13-brei-0.2.4'
           in the propagatedBuildInputs of 'python3.13-entangled-cli-2.4.2' to use a 'python3.13-brei-0.2.4' built from the same
           version of Python

         * If 'python3.13-brei-0.2.4' is used as a tool during the build, move the reference to
           'python3.13-brei-0.2.4' in 'python3.13-entangled-cli-2.4.2' from propagatedBuildInputs to nativeBuildInputs

         * If 'python3.13-brei-0.2.4' provides executables that are called at run time, pass its
           bin path to makeWrapperArgs:

               makeWrapperArgs = [ "--prefix PATH : ${lib.makeBinPath [ brei ] }" ];

        at /nix/store/srylma2w5a09ls1p5pw97ghicf8gq3wv-source/lib/renderers.nix:181:11

[v1kko]

The version incompatibility was expected and should now be fixed (you can run nix run github:entangled/entangled.py --no-write-lock-file --refresh) to check it

[v1kko]

quick question, what to i type in if i want to install it declaratively ? i tried inputs.entangled.packages.${pkgs.stdenv.hostPlatform.system}.entangled but it didn't work

If you have a flake based direnv system something like this should work:

{
  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
  inputs.entangledpkgs.url = "github:entangled/entangled.py";

  outputs = { self, nixpkgs, entangledpkgs, ... }:
    let
      pkgs = import nixpkgs { system = "x86_64-linux"; config.allowUnfree = true; };
    in
    with pkgs; {
      devShell.x86_64-linux =
        mkShell { buildInputs = [
          entangled
        ];
    };
  };
}

( I might have made a typo , probably the nixpkgs isnt even needed here )

For a non flake system I would think you have to extract the derivation and use that, or use this as an overlay, unfortunately I have less experience with that.

[claymorwan]

it is flake based, but i wanna be able to install it system wide with environment.systemPackages

[claymorwan]

ok using inputs.entangled.packages.${pkgs.stdenv.hostPlatform.system}.default i get this error

error:
       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'nixos-system-nixos-laptop-26.05.20260126.bfc1b8a'
         whose name attribute is located at /nix/store/12azrzlywd7jmsg1q9n4dpqqgb33p2wl-source/pkgs/stdenv/generic/make-derivation.nix:536:13

       … while evaluating attribute 'buildCommand' of derivation 'nixos-system-nixos-laptop-26.05.20260126.bfc1b8a'
         at /nix/store/12azrzlywd7jmsg1q9n4dpqqgb33p2wl-source/nixos/modules/system/activation/top-level.nix:69:7:
           68|       passAsFile = [ "extraDependencies" ];
           69|       buildCommand = systemBuilder;
             |       ^
           70|

       … while evaluating the option `environment.etc.dbus-1.source':

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: Python version mismatch in 'python3.13-entangled-cli-2.4.2':

       The Python derivation 'python3.13-entangled-cli-2.4.2' depends on a Python derivation
       named 'python3.13-brei-0.2.4', but the two derivations use different versions
       of Python:

           'python3.13-entangled-cli-2.4.2' uses /nix/store/slhpx9glq7vl99bwi93bgrhn3syv98s1-python3-3.13.11
                    'python3.13-brei-0.2.4' uses /nix/store/qzc04a3npl70cyyy6flnnrb2ig3kayxm-python3-3.13.11

       Possible solutions:

         * If 'python3.13-brei-0.2.4' is a Python library, change the reference to 'python3.13-brei-0.2.4'
           in the propagatedBuildInputs of 'python3.13-entangled-cli-2.4.2' to use a 'python3.13-brei-0.2.4' built from the same
           version of Python

         * If 'python3.13-brei-0.2.4' is used as a tool during the build, move the reference to
           'python3.13-brei-0.2.4' in 'python3.13-entangled-cli-2.4.2' from propagatedBuildInputs to nativeBuildInputs

         * If 'python3.13-brei-0.2.4' provides executables that are called at run time, pass its
           bin path to makeWrapperArgs:

               makeWrapperArgs = [ "--prefix PATH : ${lib.makeBinPath [ brei ] }" ];

        at /nix/store/srylma2w5a09ls1p5pw97ghicf8gq3wv-source/lib/renderers.nix:181:11