Just to note here, the Brave browser (https://brave.com/) requires user
namespaces. With Debian's default kernel, you currently get this error
when starting Brave:
$ brave-browser
[8918:8918:0304/181514.182194:FATAL:zygote_host_impl_linux.cc(116)]
No usable sandbox! Update your kernel or see
https://chromium.googlesource.com/chromium/src/+/master/docs/linux_suid_sandbox_development.md
for more information on developing with the SUID sandbox. If you want to
live dangerously and need an immediate workaround, you can try using
--no-sandbox.
Trace/breakpoint trap
And you need to start Brave with --no-sandbox. This can be solved with a
custom kernel that has CONFIG_USER_NS=y in its config.
From this discussion though, it does seem like this may be disabled by
default for good reasons..
