I’m not sure of the recommended method to fix that on Ubuntu, but evidently what is wrong is that you do not have sufficient privileges to set up the UID and GID mappings to use namespaces for rootless containers. Here’s the business end of it.
There are two files /etc/subuid and /etc/subgid that have mappings for your user.
subuid:
grogan:100000:65536
subgid (same):
grogan:100000:65536
That’s allowing me to map starting at that range, with that count of UID’s and GIDs. I believe this is functionality provided by the “shadow” package, newuidmap and newgidmap utilities. I don’t know if Ubuntu splits that package though. (you should have /usr/bin/newuidmap).
These hoops are so you don’t have to set your container application (e.g. bwrap) SUID root.
Ubuntu 24 went to apparmor, and does not have a working default for bwrap, and even with entries in /etc/subuid etc. it will still give permission denied.
Two realistic choices, depending on your security preference - create an apparmor file with an appropriate entry, or apply setuid on /usr/bin/bwrap
If you search for “Ubuntu 24.04 and Bubblewrap” you’ll find a few posts about it.
On Ubuntu 24.04, clone the lutris code from the git source and run in terminal using:
env LUTRIS_EXPERIMENTAL_FEATURES_ENABLED=1 ./lutris
from the lutris/bin folder in the code you downloaded. There are issues if you are using the 0.5.17 deb install, a lot of fixes in the git code for the um integration.
Proton GE doesn’t seem to like running BNet outside Steam where it happily runs WoW and OW2. Proton experimental does work with BNet in lutris as launched above.