Steam fails to launch with patched bwrap

The NixOS wiki says that SteamVR will only use async reprojection if it has CAP_SYS_NICE on AMD gpus (link). I tried the bubblewrap approach, and I was able to succeed in creating a patch for bubblewrap.c like the wiki says. However, once I rebuild and boot into the system, steam will refuse to launch, it gives me the error bwrap: Unexpected capabilities but not s
etuid, old file caps config? once it gets to steamwebhelper:
Starting steamwebhelper with steamrt steam runtime at $HOME/.local/share/
Steam/steamrt64/pv-runtime/steam-runtime-steamrt/_v2-entry-point
And it never launches.

I tried workarounds like setting STEAM_DISABLE_SANDBOX=1 variable (it didn’t work), and I followed issues like https://github.com/NixOS/nixpkgs/issues/217119, but no one is mentioning steam refusing to launch.

I managed to get it working by deleting the ~/.local/share/Steam directory and letting it re-download everything. You can create the symlink to the patched bwrap after that.