[rtu8lu]

I have something like this in my overlays.nix:

  self: super:
  
  let
    callPackage = super.callPackage;
  in {
    darktable = callPackage
      ./pkgs/darktable { inherit (super) darktable; };
  }

And my default.nix in pkgs/darktabele looks like this:

  { darktable, fetchurl, ... }:
  
  darktable.overrideAttrs (_: rec {
    version = "3.0.0";
    src = fetchurl {
      url = "https://github.com/darktable-org/darktable/releases/download/release-${version}/darktable-${version}.tar.xz";
      sha256 = "7195a5ff7ee95ab7c5a57e4e84f8c90cc4728b2c917359203c21293ab754c0db";
    };
  })

[therein]

Thank you. I was able to move forward similarly as well. Good to see the solution I arrived at isn't too far from yours.

  self: super:
  {
    electrum = super.electrum.overrideAttrs(old: rec {
      preBuild = old.preBuild + ''
        # Patch unnecessarily tight dependency on ecdsa version
        substituteInPlace ./contrib/requirements/requirements.txt --replace 'ecdsa>=0.14' 'ecdsa>=0.13'
  
      additionalInputs = with super.python37Packages; [
        python-jsonrpc-server
      ];
  
      propagatedBuildInputs = old.propagatedBuildInputs ++ additionalInputs;
  
      src = super.fetchFromGitHub {
        owner = "spesmilo";
        repo = "electrum";
        rev = "223b62554ead397bb94013c0d9c95b63a0708ea6";
        sha256 = "05djndhdggsw0r9pqn3gnb31nvzghgcsg05r3f7b6hwz84zbl22r";
        fetchSubmodules = true;
      };
    });
  }

[iso-8859-1]

how do you know the dependency bound is too tight?