In reply to@angryant:envs.net
Ah yes with that package already bringing in the binaries, you should have a look where those binaries end up in the store and add the path to the containing folder to LD_LIBRARY_PATH in your patch for the python package which fails to load them. mitsuba I believe?

WARNING:root:The `mitsuba` package relies on `drjit`
and needs it to be installed at a specific location. 
Currently, `drjit` is located at 
"/nix/store/d0a6r1bz06sd6p5y7cy7dkai9qi8n79w-python3.10-drjit-0.4.4/lib/python3.10/site-packages/drjit"
when it is expected to be at
"/nix/store/9i58bxc70ya01jgq1x1k7843jgv5mjvw-python3.10-mitsuba-3.5.0/lib/python3.10/site-packages/drjit".
This can happen when both packages are not installed in the same Python environment.
You will very likely experience linking issues if you do not fix this.

ImportError: The 'mitsuba' native modules could not be imported.
You're likely trying to use Mitsuba within a Python binary
(/nix/store/0raqv2didf2vabgx1rq6s2qrl9jwp004-python3-3.10.13-env/bin/python3.10)
that is different from the one for which the native module was compiled (/opt/python/cp310-cp310/bin/python).

overrides = poetry2nix.overrides.withDefaults (final: prev: {

  mitsuba = prev.mitsuba.overridePythonAttrs (old: {
    nativeBuildInputs = (old.buildInputs or [ ]) ++ [ final.drjit ];
    buildInputs = (old.buildInputs or [ ]) ++ [ pkgs.libllvm ];
  });
...

postFixup = pkgs.lib.strings.concatStrings [
  (old.postFixup or "")
  "\n"
  "ln -s ${final.drjit}/lib/python3.10/site-packages/drjit $out/lib/python3.10/site-packages/drjit"
];