Markitdown-mcp not installable. (Behaves like non existant)

The package is available (see NixOS Search)

But when trying to install it it behaves like it is non existant, not just in my configuration:

nix shell nixpkgs#markitdown-mcp
error: flake 'flake:nixpkgs' does not provide attribute 'packages.x86_64-linux.markitdown-mcp', 'legacyPackages.x86_64-linux.markitdown-mcp' or 'markitdown-mcp'

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

       … while evaluating derivation 'shell'
         whose name attribute is located at /nix/store/zml54rvr3wy3j177765pii32852zrv4p-source/pkgs/stdenv/generic/make-derivation.nix:541:13

       … while evaluating attribute 'buildInputs' of derivation 'shell'
         at /nix/store/zml54rvr3wy3j177765pii32852zrv4p-source/pkgs/stdenv/generic/make-derivation.nix:593:13:
          592|             depsHostHost = elemAt (elemAt dependencies 1) 0;
          593|             buildInputs = elemAt (elemAt dependencies 1) 1;
             |             ^
          594|             depsTargetTarget = elemAt (elemAt dependencies 2) 0;

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

       error: undefined variable 'markitdown-mcp'
       at «string»:1:107:
            1| {...}@args: with import <nixpkgs> args; (pkgs.runCommandCC or pkgs.runCommand) "shell" { buildInputs = [ (markitdown-mcp) ]; } ""
             |

nix registry list?

And also, if you build your system from a flake, what’s your nixpkgs there?

There are three Methode that dont work

  1. is using nixpkgs/unstable als flake input
  2. is nix shell nixpkgs#markitdown-mcp which uses nixpkgs/master?
  3. is nix-shell -p propably irrelevant

nix registry list?

And also, if you build your system from a flake, what’s your nixpkgs there?

What exactly does nixpkgs/unstable mean? An unstable branch does not exist

No, it uses whatever your registry points to, that’s why I asked for it.

Usually just resolves to the same thing as your flake registries nixpkgs.

The response to nix registry list is the following

user   flake:nixpkgs-unstable github:NixOS/nixpkgs/nixpkgs-unstable
system flake:nixpkgs path:/nix/store/ib2yidi0ql2j9vp3khg5lpv4ayncgs9p-zml54rvr3wy3j177765pii32852zrv4p-source?narHash=sha256-O1XDr7EWbRp%2BkHrNNgLWgIrB0/US5wvw9K6RERWAj6I%3D%0A
global flake:agda github:agda/agda
global flake:agenix github:ryantm/agenix
global flake:arion github:hercules-ci/arion
global flake:blender-bin github:edolstra/nix-warez?dir=blender
global flake:bundlers github:NixOS/bundlers
global flake:cachix github:cachix/cachix
global flake:composable github:ComposableFi/composable
global flake:disko github:nix-community/disko
global flake:dreampkgs github:nix-community/dreampkgs
global flake:dwarffs github:edolstra/dwarffs
global flake:emacs-overlay github:nix-community/emacs-overlay
global flake:fenix github:nix-community/fenix
global flake:flake-parts github:hercules-ci/flake-parts
global flake:flake-utils github:numtide/flake-utils
global flake:helix github:helix-editor/helix
global flake:hercules-ci-agent github:hercules-ci/hercules-ci-agent
global flake:hercules-ci-effects github:hercules-ci/hercules-ci-effects
global flake:home-manager github:nix-community/home-manager
global flake:hydra github:NixOS/hydra
global flake:mach-nix github:DavHau/mach-nix
global flake:ngipkgs github:ngi-nix/ngipkgs
global flake:nickel github:tweag/nickel
global flake:nix github:NixOS/nix
global flake:nix-darwin github:nix-darwin/nix-darwin
global flake:nix-serve github:edolstra/nix-serve
global flake:nixops github:NixOS/nixops
global flake:nixos-anywhere github:nix-community/nixos-anywhere
global flake:nixos-hardware github:NixOS/nixos-hardware
global flake:nixos-homepage github:NixOS/nixos-homepage
global flake:nixos-search github:NixOS/nixos-search
global flake:nixpkgs github:NixOS/nixpkgs/nixpkgs-unstable
global flake:nixvim github:nix-community/nixvim
global flake:nur github:nix-community/NUR
global flake:patchelf github:NixOS/patchelf
global flake:poetry2nix github:nix-community/poetry2nix
global flake:pridefetch github:SpyHoodle/pridefetch
global flake:sops-nix github:Mic92/sops-nix
global flake:systems github:nix-systems/default
global flake:templates github:NixOS/templates

I see the error. I was using the wrong branch as nixpkgs-unstable input. It should have been nixos-unstable all along