gamemoderun steam fails

[JustCauseWhyNot]

Describe the bug

gamemoderun steam

gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
steam.sh[4626]: Running Steam on gentoo 1.0.0.79 64-bit
steam.sh[4626]: STEAM_RUNTIME is enabled by the user
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
setup.sh[4739]: Steam runtime environment up-to-date!
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
gamemodeauto: 
steam-runtime-check-requirements[4778]: E: Cannot run /usr/bin/bwrap: wait status 11
steam-runtime-check-requirements[4778]: E: Cannot run /home/justcausewhynot/.local/share/Steam/ubuntu12_32/steam-runtime/amd64/usr/libexec/steam-runtime-tools-0/srt-bwrap: wait status 11
steam.sh[4626]: Error: Steam on Linux now requires the ability to create new user namespaces.

If the file /proc/sys/kernel/unprivileged_userns_clone exists, check that
it contains value 1.

If the file /proc/sys/user/max_user_namespaces exists, check that its
value is high enough.

This requirement is the same as for Flatpak, which has more detailed
information available:
https://github.com/flatpak/flatpak/wiki/User-namespace-requirements

I've checked and ~/unprivileged_userns_clone does have value of 1, and ~/max_user_namespaces has a value of 128157.

To Reproduce
Steps used to reproduce the behavior:

1. Launch gamemod with gamemoderun steam
2. Run game can't. If you run steam, and gamemodrun in launch options for cs2 it crashes a lot.
3. View output output pasted above.
4. See error same as 3.

Expected behavior
The ability to run gamemodrun and steam together.

System Info (please complete the following information):

• OS and version: Gentoo
• GameMode Version 1.8.1

Additional context

[smcv]

This is probably the same thing as ValveSoftware/steam-runtime#658, which seems to be indirectly caused by #347.