Dandellion: https://github.com/nodejs/node/blob/2849283c4cebbfbf523cc24303941dc36df9332f/src/node_options.cc#L924

so it is allowed in NODE_OPTIONS, which is evident by the package building.

what was your overlay? how can i reproduce this?

configurePhase = ''
        runHook preConfigure
        export HOME=$PWD/tmp
        export NODE_OPTIONS=--openssl-legacy-provider
        mkdir -p $HOME
        ${pkgs.fixup_yarn_lock}/bin/fixup_yarn_lock yarn.lock
        yarn config --offline set yarn-offline-mirror $offlineCache
        yarn install --offline --frozen-lockfile --ignore-platform --ignore-scripts --no-progress --non-interactive
        patchShebangs node_modules
        # Replace with my matrix-react-sdk
        rm -rf node_modules/matrix-react-sdk
        ln -s ${matrix-react-sdk} node_modules/matrix-react-sdk
        runHook postConfigure
      '';

based on summerevans stuff

with matrix-react-sdk being a callPackaged:

{ lib
, stdenv
, fetchpatch
, fetchFromGitHub
, fetchYarnDeps
, writeText
, jq
, yarn
, fixup_yarn_lock
, nodejs
}: stdenv.mkDerivation rec {
  pname = "matrix-react-sdk";
  version = "3.57.0";

  src = fetchFromGitHub {
    owner = "matrix-org";
    repo = "matrix-react-sdk";
    rev = "v${version}";
    sha256 = "sha256-duwjxaS4dKn/GbgykqLdQAjXeBG8kt5dhGa+O9iJacg=";
  };

  offlineCache = fetchYarnDeps {
    yarnLock = src + "/yarn.lock";
    sha256 = "sha256-Y/0hyLO78e4KGMfoCRy6bF7tU6rn6LwEcDt5afWTR6U=";
  };

  patches = [
    # All of my patches to matrix-react-sdk
    (fetchpatch {
      url = "https://github.com/sumnerevans/matrix-react-sdk/commit/ed00c00901c1741042162924bba5e800eee71402.patch";
      sha256 = "sha256-YNXRGlTDhYdIeciVRNkERqg366OYVgUaQWFAY9aP1p4=";
    })
  ];

  nativeBuildInputs = [ yarn fixup_yarn_lock jq nodejs ];

  configurePhase = ''
    runHook preConfigure

    export HOME=$PWD/tmp
    mkdir -p $HOME

    fixup_yarn_lock yarn.lock
    yarn config --offline set yarn-offline-mirror $offlineCache
    yarn install --offline --frozen-lockfile --ignore-platform --ignore-scripts --no-progress --non-interactive
    patchShebangs node_modules

    runHook postConfigure
  '';

  buildPhase = ''
    runHook preBuild
    node_modules/.bin/babel -d lib --verbose --extensions \".ts,.js,.tsx\" src
    runHook postBuild
  '';

  installPhase = ''
    runHook preInstall
    cp -R . $out
    runHook postInstall
  '';
}

In reply to @winterqt:nixos.dev
also wait Sandro 🐧 what were you setting NODE_OPTIONS to? that's not in the version of the hoon you sent, so i don't think it'll reproduce this issue