Dear Maintainer,

Attempt to launch Epiphany or DevHelp from a command line and receive this
error:
"bwrap: Creating new namespace failed: No space left on device"

I have no idea why it shows I've use 36.1 GiB of 91.1GiB of disk space, I
should have room?
If I click on the Icon for either program it doesn't even appear to do anything
at all.

This is the error you get if the limit on user namespaces (or any other
limited resource) is exceeded. The error message that comes from the kernel
is a bit misleading; I have a merge request open upstream to special-case
this error condition to have a different error message, but it hasn't been
reviewed by a maintainer.
...

If you've set the maximum number of user namespaces to 0, then bubblewrap
cannot work (unless it's setuid root, which I wouldn't recommend). See
/usr/share/doc/bubblewrap/README.Debian.gz for details.

Other container-based tools probably also can't work with this limit set
to 0. I would recommend leaving it at its default (which depends on how
much RAM you have, but is typically in the tens of thousands).

    smcv

Hi Simon,
"If you've set the maximum number of user namespaces to 0, then

I didn't set that, Bubblewrap is as Debian set it up, I've never
touched any configuration files for this program. So what is the
default for this with 8GB RAM?

This is a more general Linux kernel parameter, not specific to
bubblewrap, which affects bubblewrap and anything else that relies on
Linux namespaces. Installing the bubblewrap package does not change it.

It might be set to 0 during boot by /etc/sysctl.conf, a file in
/etc/sysctl.d, or a file in /usr/lib/sysctl.d, in which it's referred
to as "user.max_user_namespaces".

It might also be changed by some privileged program writing to
/proc/sys/user/max_user_namespaces directly, or running the sysctl
command.

I don't know specifically, but I'd guess slightly more than 30000 (it's
63652 on a system with 16G RAM).

    smcv