Change:
The one in is more up-to-date (1.0a3 vs 1.0a1, current version is 1.0a4 though), . The second one is the oldest though. Not sure what is the best solution here. It doesn't seem to make much sense to have Hy being considered a interpreter instead of a Python package (it even has attribute that AFAIK isn't any different from simply from using with and other dependencies as ). But I don't have sufficient context here. We probably need to merge one in another and delete the other derivation. Steps to reproduce the behavior: We should only have one Hy package. N/A N/A <!-- Please @ people who are in the list of the offending package or module. If in doubt, check for whoever last touched something. -- () () () Please run and paste the result.
Created a PR removing and keeping , while also making has the same parameter for backwards compatibility:

Discussion:
<del> { lib , python3Packages , hyDefinedPythonPackages /* Packages like with python.withPackages */ , ... }: python3Packages.buildPythonApplication rec { pname = "hy"; version = "1.0a1"; src = python3Packages.fetchPypi { inherit pname version; sha256 = "sha256-lCrbvbkeutSNmvvn/eHpTnJwPb5aEH7hWTXYSE+AJmU="; }; checkInputs = with python3Packages; [ flake8 pytest ]; propagatedBuildInputs = with python3Packages; [ appdirs astor clint colorama fastentrypoints funcparserlib rply pygments ] ++ (hyDefinedPythonPackages python3Packages); # Hy does not include tests in the source distribution from PyPI, so only test executable. checkPhase = '' $out/bin/hy --help > /dev/null ''; meta = with lib; { description = "A LISP dialect embedded in Python"; homepage = "https://hylang.org/"; license = licenses.mit; maintainers = with maintainers; [ nixy mazurel ]; platforms = platforms.all; }; } </del>

<del> { lib , callPackage , hyDefinedPythonPackages ? python-packages: [] /* Packages like with python.withPackages */ }: let withPackages = ( python-packages: callPackage ./builder.nix { hyDefinedPythonPackages = python-packages; } ); in (withPackages hyDefinedPythonPackages) // { # Export withPackages function for hy customization inherit withPackages; } </del>

, colorama , fetchFromGitHub , funcparserlib <ins> , hy </ins> , pytestCheckHook <ins> , python </ins> , pythonOlder , rply <ins> , testers , toPythonApplication , hyDefinedPythonPackages ? python-packages: [ ] /* Packages like with python.withPackages */ </ins> }: buildPythonPackage rec { pname = "hy"; <del> version = "1.0a3"; </del> <ins> version = "1.0a4"; format = "setuptools"; </ins> <del> disabled = pythonOlder "3.6"; </del> <ins> disabled = pythonOlder "3.7"; </ins> src = fetchFromGitHub { owner = "hylang"; repo = pname; rev = version; <del> sha256 = "1dqw24rvsps2nab1pbjjm1c81vrs34r4kkk691h3xdyxnv9hb84b"; </del> <ins> sha256 = "sha256-MBzp3jqBg/kH233wcgYYHc+Yg9GuOaBsXIfjFDihD1E="; </ins> }; <ins> # https://github.com/hylang/hy/blob/1.0a4/get_version.py#L9-L10 HY_VERSION = version; </ins> propagatedBuildInputs = [ colorama funcparserlib <del> rply ] ++ lib.optionals (pythonOlder "3.9") [ </del> <ins> rply # TODO: remove on the next release ] ++ lib.optionals (pythonOlder "3.9") [ </ins> astor <del> ]; </del> <ins> ] # for backwards compatibility with removed pkgs/development/interpreters/hy # See: https://github.com/NixOS/nixpkgs/issues/171428 ++ (hyDefinedPythonPackages python.pkgs); </ins> checkInputs = [ pytestCheckHook

pythonImportsCheck = [ "hy" ]; <ins> passthru = { tests.version = testers.testVersion { package = hy; command = "hy -v"; }; # also for backwards compatibility with removed pkgs/development/interpreters/hy withPackages = python-packages: (toPythonApplication hy).override { hyDefinedPythonPackages = python-packages; }; }; </ins> meta = with lib; { <del> description = "Python to/from Lisp layer"; homepage = "https://github.com/hylang/hy"; </del> <ins> description = "A LISP dialect embedded in Python"; homepage = "https://hylang.org/"; changelog = "https://github.com/hylang/hy/releases/tag/${version}"; </ins> license = licenses.mit; <del> maintainers = with maintainers; [ fab ]; </del> <ins> maintainers = with maintainers; [ fab mazurel nixy thiagokokada ]; </ins> }; }

<ins> { lib , buildPythonPackage , fetchFromGitHub , hy , pytestCheckHook , pythonOlder }: buildPythonPackage rec { pname = "hyrule"; version = "0.1"; format = "setuptools"; disabled = pythonOlder "3.7"; src = fetchFromGitHub { owner = "hylang"; repo = pname; rev = version; sha256 = "sha256-sqS5vOcbln+Vfv/Ji/8rJ4GTQpXIuhgf+MukjV0Kkuw="; }; propagatedBuildInputs = [ hy ]; checkInputs = [ pytestCheckHook ]; # Some tests depends on hy on PATH preCheck = "PATH=${hy}/bin:$PATH"; pythonImportsCheck = [ "hyrule" ]; meta = with lib; { description = "Hyrule is a utility library for the Hy programming language"; homepage = "https://github.com/hylang/hyrule"; changelog = "https://github.com/hylang/hylure/releases/tag/${version}"; license = licenses.mit; maintainers = with maintainers; [ thiagokokada ]; }; } </ins>

simplenote = callPackage ../applications/misc/simplenote { }; <del> hy = callPackage ../development/interpreters/hy {}; </del> <ins> hy = python3Packages.hy.withPackages (python-packages: [ ]); </ins> wmic-bin = callPackage ../servers/monitoring/plugins/wmic-bin.nix { };

hyppo = callPackage ../development/python-modules/hyppo { }; <ins> hyrule = callPackage ../development/python-modules/hyrule { }; </ins> i2c-tools = callPackage ../development/python-modules/i2c-tools { inherit (pkgs) i2c-tools; };