OpenMW nightly can't find osgPlugins-3.6.5/

I’m trying to create a custom package for OpenMW nightly, but I’m running into some trouble. The osgPlugins-3.6.5/ plugin isn’t being found by OpenMW when I launch it:

[16:15:08.788 I] Crash handler installed
[16:15:08.897 I] Loading config file: /nix/store/6i5gv02fg59zy5847pldif6yrxhvkn1j-openmw-0.49.0/etc/openmw/openmw.cfg
[16:15:08.899 I] Loading config file: /home/cassidy/.config/openmw/openmw.cfg
[16:15:08.899 I] Logs dir: /home/cassidy/.config/openmw/
[16:15:08.899 I] User data dir: /home/cassidy/.local/share/openmw/
[16:15:08.899 I] Screenshots dir: /home/cassidy/.local/share/openmw/screenshots
[16:15:08.900 I] OpenMW version 0.49.0
[16:15:08.900 I] Loading settings file: /nix/store/6i5gv02fg59zy5847pldif6yrxhvkn1j-openmw-0.49.0/etc/openmw/defaults.bin
[16:15:08.901 I] Loading settings file: /home/cassidy/.config/openmw/settings.cfg
[16:15:08.901 I] Using default (English) font encoding.
[16:15:08.901 W] No such dir: /home/cassidy/.local/share/openmw/data
[16:15:08.902 E] Missing OSG plugin: osgPlugins-3.6.5/

I’ve checked inside of the of the Nix store directory for openscenegraph, and it indeed isn’t there, even though all the other needed plugins are. This issue isn’t occuring with the nixpkgs version of OpenMW.

Here’s my custom package: nixos/packages/openmw-nightly/package.nix at 3e80fbafd1499c783c01ec96f8b698a8a623fb33 - PopeRigby/nixos -

Here’s the nixpkgs version for reference: nixpkgs/pkgs/games/openmw/default.nix at 051f920625ab5aabe37c920346e3e69d7d34400e · NixOS/nixpkgs · GitHub