How to debug an application in a kube pod with gdb without capabilities, CRD or privileged user?

Question

In a distant kube cluster I have some pod with C++ application. I need to debug them with gdb or gdbserver but :

• No capabilities (like SYS_PTRACE) allowed on the images
• No privileged user
• No CustomResourceDefinitions allowed in the cluster
• No SELinux in the images (it's a no from the security team)

I tried Squash (can't use CRD), NSenter (no access to the host, only some access to create or delete kube resources), SELinux (not possible), can't edit /proc/sys/kernel/yama/ptrace_scope.