here is my package.nix as it is:

{
  lib,
  buildNpmPackage,
  fetchFromGitHub,
}:

buildNpmPackage (finalAttrs: {
  pname = "prisma-language-server";
  version = "6.16.2";

  src = fetchFromGitHub {
    owner = "prisma";
    repo = "language-tools";
    tag = "v${finalAttrs.version}";
    hash = "sha256-x4lYhS8PJ5paFJDAXGtKv0kY01C/YWaJU640WlJT8Eo=";
  };

  npmDepsHash = "sha256-QMxu2AWGRQ2semp6BmOQbM7Pw/pS0mgx0P0hr60SjPs=";

  # The prepack script runs the build script, which we'd rather do in the build phase.
  npmPackFlags = [ "--ignore-scripts" ];

  makeCacheWritable = true;

  NODE_OPTIONS = "--openssl-legacy-provider";

  meta = {
    description = "";
    homepage = "https://github.com/prisma/language-tools#readme";
    license = lib.licenses.asl20;
    maintainers = with lib.maintainers; [ mmkaram ];
  };
})

I got the new package-lock.json but I'm still getting that error:

       > npm error code ENOTCACHED
       > npm error request to https://registry.npmjs.org/universal-user-agent failed: cache mode is 'only-if-cached' but no cached response is available.
       > npm error A complete log of this run can be found in: /build/cache/_logs/2025-09-18T10_22_07_289Z-debug-0.log
       >

with my package.nix:

{
  lib,
  buildNpmPackage,
  fetchFromGitHub,
}:

buildNpmPackage (finalAttrs: {
  pname = "prisma-language-server";
  version = "6.16.2";

  src = fetchFromGitHub {
    owner = "prisma";
    repo = "language-tools";
    tag = "${finalAttrs.version}";
    hash = "sha256-UZP0pLcbMeaYI0ytOJ68l/ZEC9dBhohJZyTU99p+1QM=";
  };

  npmPackFlags = [ "--ignore-scripts" ];
  makeCacheWritable = true;

  # The original lockfile from the upstream source is broken,
  # so we need to use a rebuilt version of the package-lock file.
  postPatch = ''
    cp ${./package-lock.json} package-lock.json
  '';

  npmDepsHash = "sha256-QMxu2AWGRQ2semp6BmOQbM7Pw/pS0mgx0P0hr60SjPs=";

  NODE_OPTIONS = "--openssl-legacy-provider";

  meta = {
    description = "";
    homepage = "https://github.com/prisma/language-tools#readme";
    license = lib.licenses.asl20;
    maintainers = with lib.maintainers; [ mmkaram ];
  };
})

also the error I get when the hash is wrong looks like this:

patching script interpreter paths in /nix/store/p2h78fcx52hwp92aj93p42zfgjf0q4ip-prisma-language-server-6.16.2-npm-deps
error: hash mismatch in fixed-output derivation '/nix/store/70y5ydbl5i3iil4zxl6dcgalr0wlx56r-prisma-language-server-6.16.2-npm-deps.drv':
         specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
            got:    sha256-XouMkRE1QQvr7keIF7q1jkCE21/O9jyRfbmqm820yas=

as opposed to the ENOTCACHED error I was talking about above