On Mon, 25 Jul 2022 13:56:50 -0700
Jacob Keller [off-list ref] wrote:

To avoid potential issues, only allow the attribute to be added to
commands when the kernel recognizes it. This is important because some
commands do not perform strict validation. If we were to add the
attribute without this check, an old kernel may silently accept the
command and perform an update even when dry_run was requested.

Sigh. Looks like the old kernels are buggy. The workaround in userspace
is also likely to be source of bugs.