I'm trying to rebuild the system/build my first generation: 
```
building '/nix/store/5jqga4vzivs4nbygy9fsrp72yvpxzzf4-system-path.drv'...
building '/nix/store/jdhkj1k8gzizxvmi7inral709wsvp7jy-initrd-linux-5.4.117.drv'...
cp: cannot access '/nix/store/jqlhqlrkpccsmddxjzjzhqlhvc82b9g5-linux-5.4.117-modules-shrunk/lib': Bad message
builder for '/nix/store/jdhkj1k8gzizxvmi7inral709wsvp7jy-initrd-linux-5.4.117.drv' failed with exit code 1
cannot build derivation '/nix/store/3ccmrk7v6iz9al11va8l91wa58kxvl7z-nixos-system-nixos-20.09.4095.c85e2a478c2.drv': 1 dependencies couldn't be built
error: build of '/nix/store/3ccmrk7v6iz9al11va8l91wa58kxvl7z-nixos-system-nixos-20.09.4095.c85e2a478c2.drv' failed
```
I really can't find this error anywhere, does anyone know what's happening here?