ptrace from bwrap fails when attaching to pid's that are outside of bwrap process

[haampie]

I'm not using bwrap as a sandbox, but rather just to bind mount some paths.

In that context I was hoping I could run strace -p [pid of a process that is not a subprocess of bwrap].

But trying to run strace on the parent process of bwrap itself fails:

$ bwrap --dev-bind / / strace -p $$
strace: attach: ptrace(PTRACE_SEIZE, 128146): Operation not permitted

whereas this works:

$ strace -p $$
strace: Process 128146 attached
wait4(-1,

Nothing changes with --cap-add ALL

Is there a way to get this to work?