buildLinux with vendor kernel is not installing all of the files

https://github.com/therishidesai/test-nixos/blob/ddd97c914bf3504d5408c86aef7f39046426639b/kernel/digi-linux-5-4.nix

I have this derivation to build an NXP kernel. For some reason the modules.alias files and other generated files related to kernel modules are missing, so when I try to modprobe modules with this kernel the OS can never find the module. I tried running make modules_install locally and all those files are there so there doesn’t seem to be a problem with the actual kernel itself, somehow buildLinux is swallowing those files. I even ran make modules_install after running nix develop and unpackPhase so I was using the same exact source buildLinux was using and the files weren’t missing so buildLinux is failing here with this kernel.

Any ideas as on what else I can do to debug this? Also if someone here could replicate this with the repo I linked above that would be helpful, I’m running nix build .#legacyPackages.aarch64-linux.digi-linux-5-4

linux> Warning: 'make modules_install' requires /sbin/depmod. Please install it.
linux> This is probably in the kmod package.

Found this buried in the logs