Unclear What the extra check tests and what its warning says are not known.
What
The sandbox is the walled-off area Claude Code uses to run commands safely. On Linux, Claude Code checks that the system has what the sandbox needs and lists warnings for anything missing. Before, that list came from a check for seccomp (a Linux feature that limits what a program may do) and a permission check. It now runs one extra check and adds its message to the warnings.
Why
You may see a sandbox warning on Linux that you did not see before.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
What the extra check tests and what its warning says are not known.